Tseung Kwan O Extension - smooth sailing on a voyage of discovery
By Angela Tam
In many a hushed office of a construction industry executive, there lies a copy of the Construction Industry Review Committee (CIRC) report, detailing the problems the industry faces today and the proposed way forward.
That the problems -- safety and environmental issues, a confrontational culture, poor quality work, poor risk management, etc -- exist cannot be disputed, but, given the entrenched practices of the industry, can they be rectified as suggested?
In fact the possibility of making the recommended improvements can be gauged from the Tseung Kwan O Extension (TKE) project.
TKE is a 12.5 km long, five-station extension to the existing MTR network and the sixth line to be developed by the MTR Corporation (MRTC). Upon completion in December 2002, it would serve a population of 340,000 in Tseung Kwan O New Town. The project is divided into 13 civil engineering and building works contracts under three sections. Section 1 covers the Kwun Tong Line diversion connected to the Eastern Harbour Crossing and Yau Tong. Four stations in the new town -- Tiu Keng Leng, Tseung Kwan O, Hang Hau and Po Lam -- are grouped under section 2. Two rock tunnels, the depot and trackwork are grouped under section 3. There are also 21 E&M contracts.
The project, construction of which began in 1998/99, anticipated the CIRC report in many ways.
Map showing TKE alignment and connection to Kwun Tong and Island Lines
Introducing new initiatives
With lessons learnt from previous projects, the MTRC was determined to introduce initiatives that would not only ensure smooth progress, but also better quality work, better environmental performance, better safety record and better relationships -- all issues that were addressed in the CIRC report.
The most important initiative taken was the introduction of partnering, on an informal basis, with partnering workshops set up to involve staff at all levels, from the directors to foremen.
A project with so many interfaces has enormous potential for conflict, and many people were initially suspicious of the partnering concept. Why, one contractor might ask, for example, should he share his experience with a competitor? As the project progressed, however, more and more people were converted and the level of trust improved.
"People were moving from confrontation to cooperation, their mindset changed," said overall TKE project manager Henry Lam. "It really enhances the day-to-day delivery of the job."
The MTRC introduced a risk management concept through the target cost incentivisation scheme, under which all outstanding works on a contract are costed for their risks and a "pain-share-gain-share" arrangement arrived at with the contractor. The corporation and the contractor share the savings if the final account turns out to be less than the target and similarly, the two split the cost if the target is exceeded. It puts a cap on the risk shouldered by the contractor and gives him an incentive to look for savings.
The result has been a smooth-running project with few claims and excellent working relationships.
"The tangible benefit is cost savings, which vary from contract to contract; and programme certainty," Mr Lam said.
The cost of the project was revised from HK$30.5 billion to HK$24 billion in 1999 and further to HK$21 billion in 2000. While this could be partly attributed to the economic downturn leading to lower tender prices, there is little doubt that the collective effort to discover ways of reducing waste is also responsible for the vast reduction, plus the savings achieved through improved management efficiencies.
The MTRC also extended the partnering spirit to its relationship with the end-user, the government departments it works with and the community.
"On the Airport Railway we just finished the job and handed it over to operations. Here we involve operations in the design process from day one, to reduce the downstream risks. We also involve government departments, giving them project presentations regularly. Enhancing project transparency has produced a very positive response," Ir Lam said.
The MTRC and its contractors also do their best to keep the community informed and to minimise the impact of the construction work on people's lives. Community liaison was made an integral part of the project and positive community relations are maintained by, for example, making school visits, and organising road shows on project progress.
In addition to the partnering and risk management initiatives, the corporation also added environmental awards to the safety and quality awards it traditionally gives out. Each site is assessed for its environmental, safety and quality performance and awards given out regularly to deserving contractors.
"We want to send a positive message to the industry and help raise the performance level of the industry," Mr Lam said.
Well-thumbed copies of the report are being consulted again and again at the MTRC as the corporation seeks to carry the initiatives already taken to the next stage.
"TKE is a voyage of discovery," Mr Lam said. "We want to make further improvements in future projects in light of the recommendations contained in the report."
Section 1 of TKE involves the critical works associated with the new extension's interface with the existing MTR network. Both civil contracts in this section are progressing well, according to section project manager Roger Bayliss.
Yau Tong Station
Kumagai Gumi Co Ltd, which won the HK$457 million contract to construct Yau Tong Station, will give track access earlier than programmed. The four-level, 9,855 sq m station is the biggest station on TKE. As a key interchange station where passengers will change trains for Tseung Kwan O, Kwun Tong or Quarry Bay, it has a configuration designed to facilitate cross-platform interchange.
Trains heading west to North Point or east to Tiu Keng Ling arrive at the underground lower platform while trains bound for Po Lam and Yau Ma Tei respectively arrive at an upper platform at ground level. The concourse is on the first floor and connected to a neighbouring housing estate via footbridges. A commercial spine will eventually be added to the roof above the third floor plant room, to be linked to two new housing estates.
The eastern half of the station occupies a hillside which was excavated to accommodate the structure. The western half of the station is founded on piles. The project involves a considerable amount of works entrusted by the Housing Authority, including the commercial spine to be built on the roof and the foundation for future housing development at the west end of the station.
All foundation works have been completed and the superstructure is now emerging from the ground. Architectural works have commenced. The platform levels will be handed over to the trackwork contractor up to ten weeks earlier than programmed under an incentivisation scheme initiated by the MTRC.
As a development of the MTRC's partnering initiative, Incentivisation Agreements have been entered into with a number of contractors on TKE under which the contractor and the corporation manage the works together and share the consequent benefits or losses.
In developing the agreement with Kumagai, the two parties jointly prepared a risk register which identified all potential risks facing the project to completion. By sharing the experience of both parties, the risk register provided a realistic basis for working out the target cost for the shared risks. Savings or additions against the target cost will be shared. This arrangement encourages proactive joint management of problems.
"Incentivisation has brought the two parties closer together. Now we have joint ownership of the problems and issues and both parties are working together to resolve them," said Ir Bayliss. "We concluded the agreement before Christmas (2000) and revised the programme, confirming that some of the dates could be brought forward."
The contract for Yau Tong Station also calls for the construction of a ventilation building. This is a straightforward RC structure but its construction requires coordination with the contractor of Black Hill Tunnels as the building is constructed over a ventilation shaft constructed under the Black Hill Tunnels contract.
EHC and Lam Tin Tunnels
To the west of Yau Tong Station is the Eastern Harbour Crossing (EHC) and Lam Tin Tunnels, a contract being carried out by a joint venture between Gammon Construction and China Harbour Engineering Co.
This is a complex project involving the construction of a connection to the Eastern Harbour Crossing as it emerges at the Kowloon landfall. The existing tunnel floor has been anchored down to the rock to avoid uplift and the existing roof is now suspended from a new roof. Both of these operations were required to allow the existing tunnel walls to be removed, to provide space for the trackwork junction. A complex sequence of work has been completed, much of it in the middle of the night during non- traffic hours, without disrupting normal train operations.
The 450m long cut-and-cover tunnels between the EHC connection and the new Yau Tong Station have an interesting configuration. The two tracks start from the EHC end side by side then gradually twist around, on a curve, arriving at Yau Tong with one track above the other. This is required to facilitate the cross platform interchange facility at Yau Tong Station.
The proximity of the cut-and-cover tunnel to the EHC toll plaza has called for careful planning of the construction methods, according to Ir Bayliss. In the first section, next to the EHC connection, a section of the existing EHC structural approach slab has been underpinned to allow excavation and RC works to take place. In the next section, where the EHC slab gives way to conventional flexible road construction, a works area 30 m long and up to 2.5 m wide was temporarily taken from the toll plaza to install 600 mm diameter pipe piles. These piles act as a retaining wall that allow excavation 14 m down to formation level for the cut-and-cover tunnel.
Further on the next section of the tunnel cuts across the EHC service road, which is used by vehicles belonging to the tunnel company to enter the southbound tunnel. The service road has been diverted onto a temporary bridge to allow excavation to take place underneath. This will be the last piece of excavation to be carried out for the cut-and-cover tunnel as excavation of the next section, underneath the new Cha Kwo Ling ventilation building, has already been completed. Construction of the tunnel structures is underway using conventional RC techniques. Access for tracklaying is expected to be provided by late July this year.
The project involves a large amount of entrusted works for the Housing Authority and Highways Department. The contractor is undertaking site formation work on a 13.7 ha area, of which 11.5 ha is entrusted work for the Housing Authority. The housing area will be handed over to the authority in three phases beginning in April 2001.
In all some 1.9 million cu m of material is being excavated, 1.3 million cu m being rock. Much of the excavation is carried out by drill-and-blast. In areas adjacent to roads, utilities, sensitive structures or the EHC, excavation is being carried out by mechanical plant. In some areas chemical expansion agent is also being used, in a similar way to explosive, but with the agent being left in the drill hole to expand over a period of time as opposed to immediate detonation/explosion.
Disposal of the material is by marine barge to a number of locations in Hong Kong, to avoid traffic congestion. A temporary bridge has been built over Cha Kwo Ling Road to enable the excavated material to be transported directly form the site to a loadout area in Yau Tong Bay, where it is crushed and loaded onto barges.
The contractor is also reprovisioning Yau Tong Road, which in its original alignment cut through the middle of Yau Tong station. It is also being widened for the Highways Department. The road will be re-opened in the spring of 2002.
Cross section of Yau Tong Station
Working close to the EHC toll plaza
With the wet trades moving in, most of the stations on TKE are now racing towards the finish with Po Lam Station leading the way.
Section 2 of the project covers the construction of four of the five stations: Po Lam, Hang Hau, Tseung Kwan O and Tiu Keng Leng.
Putting the finishing touches on Po Lam Station
Po Lam Station
Po Lam Station, which was topped out in December last year, owes its speedy progress to one key factor: partnering. The concept was used to get the MTRC's consultants as well as design, construction and operation teams to sit down together, to work on a rationalised design following changes to plans for a depot at Yau Tong Wan.
The original Po Lam design was for a large, three-level station with long platforms because it had to be capable of handling trains passing through en route to a Yau Tong Wan depot at two-minute headway. However, this was no longer necessary following the depot's move to Tseung Kwan O South, so the teams had six weeks in which to review the design.
By reducing the number of platforms from two to one and amalgamating some plant rooms to save more space, they arrived at a two-level station with a smaller, at grade concourse with the ticketing hall and platform all in the same area. HK$200 million was saved and the Chairman's Award was won.
Partnering continues to play an important role in the project, ensuring good relationships between client and the contractor, Maeda Corporation. According to section 2 project manager Roger Bettiss, both the tracklaying and building services contractors were given access to Po Lam Station six weeks ahead of schedule and no outstanding claims or contractual issues have arisen whatsoever, reflecting both the success of the contract and the partnering initiative.
The station will be connected to neighbouring residential developments and a public transport interchange (PTI) via five footbridges. Two of these are steel structures that are prefabricated in China and transported to site for lifting into position, a precise operation requiring the cooperation of the police and the local community as it necessitated road closure during daylight hours. All five footbridges have been completed and one is already in operation, allowing a temporary, heavily used walkway which crossed the site to be removed so that work on the station structure could be completed.
Po Lam Station is one of the first contracts on TKE to have target cost incentivisation agreements signed. To manage shared risks, a Site Control Group (SCG) run by the construction manager and the contractor's project manager for each contract is set up on each site, to review proposed changes, assign the risks and agree on implementation.
"To date those groups have worked extremely well, with considerable openness and honesty," Mr Bettiss said. "Because of the nature of the relationships we have been able to achieve a lot without the need for claims."
Hang Hau Station
Hang Hau Station is expected to be the next station to be topped out, or, as the contractor, Dragages et Travaux Public preferred to describe it, "bottomed out", in reference to the topdown method used for its construction.
Hang Hau Station involves the construction of an underground station, property enabling works for six future residential towers, a major traction infeed substation, a ventilation building and 1.2 km of cut-and-cover tunnels, together with government-entrusted road works above the tunnels.
The original design for the station called for the excavation of a 140 m x 90 m x 20 m deep footprint within a sheet pile and slurry cofferdam wall followed by construction of the station superstructure. The alternative topdown method proposed by the contractor, however, involves the early construction of the concourse slab, which is fully strutted before excavation is carried out underneath. The concourse slab (at ground level) is supported on stanchions previously installed during bored pile construction. This allows the superstructure to be built above the slab at the same time as the track slab is constructed below.
Since a retaining wall is required to give the concourse slab the desired stability, the contractor developed a concrete permanent diaphragm wall in place of the temporary sheet piling inserted in a slurry trench filled with tremie plastic concrete as per the original design. By thus incorporating the temporary works into the permanent structure, the contractor was able to offer the MTRC the benefit of cost savings as well as early track and building services access for the station.
Continuous waterproofing is achieved within the temporary retaining structure of the property enabling works area through the installation of I beams at less than one metre intervals in a slurry wall composed of a bentonite cement mix. The mix is adequate as a water barrier even though it has a strength of below 1 MPa. With the stiffness provided by the I beams, a strong yet economical retaining structure is created which minimises the number of horizontal struts required.
The use of an open retaining structure with waterproofing provided within a slurry wall is a first in Hong Kong.
Access for the building services contractor was given at the north end of the station at platform level and track access has also been given to all tunnels from Po Lam to Hang Hau.
Work on the cut-and-cover tunnels south of Hang Hau is also going well, the MTRC and the contractor having worked closely to resolve problems arising from rock levels and temporary works. Again, the contractor was able to achieve cost and time savings, this time by redistributing some piles to the middle of the box structure, thus reducing the span between the peripheral piles and significantly reducing the need for reinforcement through the provision of additional slab support in the middle.
The tunnels are being constructed within diaphragm walls or heavily strutted sheet pile cofferdams because of their depth, especially at the bifurcation where the northbound and southbound tracks cross each other underground. Several roads and associated utilities were diverted onto temporary bridges before tunnel excavation commenced. Difficulty arising from the presence of an existing 15 m wide four-box drainage culvert above the tunnel south of the station was overcome by the installation of secant piles after breaking the culvert, to achieve waterproofing in high rock so that tunnel excavation under the culvert could be carried out in the dry.
Progress on the contract has been aided by the MTRC's ability to persuade the Territory Development Department (TDD) to entrust the construction of a section of road above the bifurcation to its contractor.
Mr Bettiss acknowledged the proactive attitude of the contractor's project manager towards cost and change control and, by embracing partnering, reducing paperwork to a minimum.
Tseung Kwan O Station
The Leighton-China State Joint Venture, the contractor for Tseung Kwan O Station, also won praise for management commitment to the partnering initiative.
Tseung Kwan O is a three-level station with underground platforms, a concourse at ground level, plant rooms on the mezzanine level and a landscape deck on top. The contractor is now finishing concreting of the roof and building services installation has commenced. Both the westbound and eastbound tracks are due to be handed over to the trackwork contractor soon, with the westbound track to be handed over at the end of February 2001 and eastbound track at the end of March 2001.
Leighton-China State's HK$1.1 billion contract also involves the construction of 700-800 m of cut-and-cover tunnels which include an overrun tunnel for trains returning to Lam Tin or Quarry Bay from the new town that goes underneath the eastbound and westbound TKE tracks at a lower level to the west of the station. The tunnels are deep because of this configuration and are founded on piles within a 1.3 km long continuous diaphragm wall, one of the longest ever installed in Hong Kong.
Tunnelling at the far end in the west has presented some challenge due to the presence of a tunnel box installed by the TDD about five years ago. The contractor has tried to plug the interface with sheet piling but has experienced considerable water inflow because the tunnel box is close to the sea front and the large circular steel cage the previous contractor used as dewatering points have acted as siphons drawing water into the TKE site. Eight-inch dewatering pumps are being used to remove the water, with an extra set on standby.
Tiu Keng Leng Station
In Tiu Keng Leng, a joint venture between Paul Y Construction and China Railways Engineering Corporation is constructing a four-level station with two underground platform levels, a concourse at ground level and plant rooms at the first level, with minipiles below designed to resist floatation.
Tiu Keng Leng Station is an interchange station providing cross-platform facilities for passengers switching between the Kwun Tong and Tseung Kwan O Lines.
The project also includes the construction of a four-storey, 24,000 sq m property podium, a PTI and 230 m of cut-and-cover tunnels to accommodate four tunnel cells.
As part of the contract an access shaft has been constructed to incorporate a 20 m long open section of tunnels to be used by the trackwork contractor to set up a base for laying 60% of the total TKE track. Track access is expected to be provided in March for tracklaying to commence eastwards.
The next 12 months will put a real test on the partnering initiative as systemwide and building services contractors will be installing their equipment while the civil contractors puts the finishing touches on the station structures; not to mention completing three PTIs at Hang Hau, Tseung Kwan O and Tiu Keng Leng stations.
Mr Bettiss has positive news for his colleagues in the property department: all three PTIs are ahead of schedule or on programme, and will soon be ready to support the property developments associated with their respective stations.
Tseung Kwan O Station
Since the two tunnels under section 3 of TKE achieved breakthrough in the middle of last year, the contractors for the Black Hill and Pak Shing Kok tunnels have been busy installing the tunnel lining for their respective projects.
The Black Hill Tunnels are 1.8 km long but involved about 8 km of tunnelling because there are four tunnels for two MTR lines plus a 600 m long centre siding where services can be reversed or disabled trains temporarily accommodated. There are also six junction chambers and two crossovers between the Kwun Tong and Tseung Kwan O lines. Construction is being carried out by a joint venture between Dumez and Chun Wo.
The 6 km Pak Shing Kok Tunnels were excavated in a mixture of volcanic rock and granite. The tunnels have a complex configuration. The tracks start at the same level on leaving the depot but the departure track gradually rolls over the top of the arrival tunnel to join the main track from the future Tseung Kwan O South station. This creates three junctions, one which allows trains leaving the depot to enter a deadend siding; and two which allow the depot tracks to join the main tracks. Hyundai-Kier is the project's contractor.
Waterproofing works in Black Hill Tunnels
Black Hill Tunnels
According to section 3 project manager David Sorton, both contractors are now installing concrete linings in their respective projects. In Black Hill Tunnels four 12 m long shutters are being used to construct the lining in the four running tunnels plus the centre siding. This is no easy task, as the contractor must ensure that access is not cut off when he moves the shutters through the tunnels and down to the centre siding.
Maintaining access is of vital importance as there is a flow of new material into the tunnels from the west and a flow of old materials out in an easterly direction. In addition, at the eastern end the contractor must give access to the neighbouring Tiu Keng Ling tunnels contractor.
At the western end the connection between the bored and cut-and-cover tunnels is being used as the main access point. The final connection between the bored tunnels and Yau Tong station, a simple reinforced concrete (RC) structure, is expected to be made by May. Access has also been provided to the Yau Tong Station contractor to facilitate construction of the ventilation building on top of the tunnel shaft.
At the eastern end an end wall has been constructed to cover the lower tubes of a 50 m cut-and-cover section. The roof of the upper tubes has been left out for the time being, however, to maintain accessibility and allow the lining shutters to be taken out. All four shutters are now approaching Tiu Keng Leng, with about 70% of all tunnel lining works completed. The contractor has also commenced construction of the firemen's walkway on either side of the track.
Pak Shing Kok Tunnels, south portal
Pak Shing Kok Tunnels
Some difficulty associated with underbreak was encountered in both Black Hill and Pak Shing Kok Tunnels. Removing the rock using mechanical breakers proved particularly challenging in the latter because of the presence of hard volcanic rock, in some instances resulting in the mechanical picks disappearing faster than the material they were supposed to remove.
As in Black Hill Tunnels, 12 m long shutters manufactured by Siform in China were used to construct the lining in the Pak Shing Kok Tunnels. In both cases the shutters are set up on short lengths of rails for moving them forward. The two contractors are using different lining methods, however.
At Black Hill, another set of shutters are used to construction a primary lining first, providing a smooth surface on which to install the waterproof membrane. At Pak Shing Kok, on the other hand, the waterproof membrane is installed on a smoothing layer of shotcrete before a structural lining of varying thickness (the average is 250 mm) is installed.
Both contracts are using mass concrete for the tunnel lining to minimise the possibility of corrosion inherent in reinforced concrete, even though the potential problem is minimised by full waterproofing. Grade 40 concrete is used in the pumping mix, delivered by concrete trucks run as close to the shutters as possible to avoid long pumping lines and therefore blockages. Generally the pumping is limited to a maximum distance of 100 m.
Superstructure works at the depot
Tseung Kwan O Depot
Also coming under Section 3 of TKE is Tseung Kwan O depot. The massive, trapezoidal structure sits on an 8.5 ha site in an area of reclaimed land subject to settlement. Because of this, the MTRC took an early decision to found the whole structure on piles. The decision is a wise one as the project has remained unaffected by a groundwater drawdown in the area.
Gammon Construction Ltd has completed the two piling contracts associated with the depot involving the installation of 830 large diameter bored piles, the longest of which reached a depth of 140 m. The two contracts brought together two keen partnering proponents: the MTRC and Gammon. Not surprisingly they were completed in a cooperative spirit: the final account was signed within days of the last pile being concreted.
AMEC International Construction Ltd (HK) is now busy constructing the depot with five tower cranes spread over the long structure. The depot accommodates a wide range of facilities. The southern, wider end of the building contains the main depot building, maintenance areas and stabling while the northern, narrower end contains the permanent way building, water wash facilities and a substation.
Slab and column construction is being carried out from both ends towards the middle because the presence of these facilities make the two ends more critical to the programme.
"It's a programme-driven decision to work from both ends," Ir Sorton explained. "The narrow end needs to be done to allow access for tracklaying. This allows the two independent teams to work together without getting under each other's feet."
Similarly, completing the wider end early would allow the building services contractor to have access, for installing the multitude of building services in the main building. The middle section of the depot is simple by comparison, consisting mainly of the track fan.
A 400 mm thick slab, supported on about 700 columns, is being constructed using a combination of SGB tableforms and proprietary falsework. Ordinary scaffolding is used in non-standard areas. About 70% of the podium slab has now been completed and the entire structure is expected to be complete in early May 2001.
Cross section of PCBT
The contractor for the tracklaying work is a joint venture comprising Barclay Mowlem, Zen Pacific and China Civil Construction. Tracklaying started in January 2001, at the depot in the south and Po Lam Station at the northern end of the extension.
On the Airport Railway the tracklaying was done using mobile flash butt welders; on TKOE however, a different method has been adopted. The contractor is keeping the flash butt welder static at each of the four main track access points at the depot, Po Lam, Tiu Keng leng and Yau Tong. The 18 m long rails are joined together to make long rails up to 180 m in length. These are then rolled down along the inverts of the tunnels and eventually joined together by thermic welding.
At Po Lam, the flash butt welder has been set up in a small depot in an overrun area to produce track up to 500 m in length. The main line track will be laid over a 45-week period, finishing where the extension joins the existing railway at Eastern Harbour Crossing. A total of 60 km of track will be laid, of which 28 km will be continuously welded main line track.
In addition to tracklaying for the extension, the contractor has also built a temporary depot with temporary trackwork adjacent to the main Tseung Kwan O depot, which will be the base for operation of electrical and mechanical (E&M) works trains.
According to Ir Sorton, two trackforms are being used on TKOE: precast concrete block trackform (PCBT), which was previously called low vibration track (LVT) or "Sonneville" track; and isolated slab track (IST) consisting of individual resilient baseplates bolted to a concrete slab cast on a rubber mat placed on the tunnel invert slab.
PCBT, which consists of individual concrete blocks sitting on a microcellular elastic pad contained in a rubber "boot", is used in tunnels and at junctions. IST is used in areas where noise and vibration control is needed; for example, where there is property development adjacent to the railway Ir Sorton said careful consideration was given to the use of floating-slab track (FST) in areas requiring noise attenuation.
"IST was chosen because it meets our noise attenuation requirements and is quicker to install, compared with FST. IST is about twice as expensive as PCBT, but FST is four to five times more expensive than PCBT."
Trackwork installation on the main line is due for completion towards the end of 2001, whilst that in the depot will continue until mid-2002.
Trackwork at Po Lam Station
Cross section of IST
Electrical and mechanical installation on TKE marked a major milestone recently when CLP Power delivered two 85-tonne, 132 kV transformers to the Tseung Kwan O infeed substation.
At the time of going to press, Hongkong Electric is due to deliver equipment for the Quarry Bay infeed substation shortly. Either one of the utilities can provide full backup to guarantee normal train service should the power supply from the other infeed substation be interrupted. Both electricity companies are progressing well and there is a good chance of both substations being energised four weeks earlier than scheduled.
Paul P H Lo
According to Paul P H Lo, MTRC's project manager (E&M), many of the E&M equipment on TKE incorporate various system enhancements compared with the existing systems. For example, in the previous line, the railway was fitted with a power supply system which steps down from 33 kV to 11 kV then 415 V. TKE, however, will be installed with a system which will step down directly from 33 kV to 415 V, thus saving both energy and equipment. The power system contract, involving the supply of 33 kV switchgear and other equipment, is the first E&M contract to be awarded by the corporation to a mainland company, CITIC Guo Hua International Contracting (Overseas) Ltd.
Other improvements include a closed circuit television system with better picture quality and which is not affected by electromagnetic interference and energy-efficient lighting. One improvement which passengers are bound to notice is the fare collection system, which will not only be more stylish, but also more user-friendly -- TKE will be fitted entirely with flap gates.
User feedback is just as important as user-friendliness. According to Ir Lo, user feedback has been taken into account in the lift design: while these will be, like the ones on the Airport Railway, glass lifts that project a sense of airy brightness, they will be fitted with conglomerate tiles rather than glass floors. Hitachi Elevator Engineering Co (HK) Ltd won a HK$29 million contract to supply 14 lifts for TKE and the first three sets have been delivered for assembly.
The benefit of completing design before construction and change control: not a single ducting reserve is in the wrong place
Extensive testing is an essential part of E&M works, and various equipment are now undergoing vigorous testing in Hong Kong and various parts of the world. For example, a prototype of the platform screen doors, which are being manufactured in Japan, has undergone the one-million cycle test in Sheung Wan Station. The 33 kV switchgear and rectifier were type-tested in the Netherlands.
With all civil works on target or ahead of programme, E&M contractors have been able to start work earlier than expected. Access for building services contractors has been provided at Po Lam, Hang Hau, Tiu Keng Leng and Tseung Kwan O stations; in total building services contractors have now been given access to 80% of the area by their civil works colleagues.
Ir Lo said programme control and coordination had been improved based on experience gained from the Airport Railway. One of the fundamental changes is the appointment of building services contractors as designated principal contractors rather than sub-contractors to main contractors. This arrangement gives the building services contractors direct access to the client and improves programme certainty for the project. It also allows the building services contractor to have full contractual responsibility for spatial coordination of all services within the allocated routes and spaces, according to his detailed design and those of the systemwide E&M contractors.
TKE also benefits from vastly improved change control. The design for the project was finalised before construction commenced and any proposal for changes is subjected to stringent scrutiny before approval can be given. As a result, the civil works have proceeded more smoothly than before and, with most stations achieving access dates earlier than expected, E&M contractors have been able to move in sooner to install their equipment.
Partnering, of course, also has a large part to play. Three layers of inter-contract workshops are organised by the MTRC to facilitate cooperation between civil and E&M contractors, cascading down from management to inspector level.
Another difference between the Airport Railway and TKE concerns maintenance of the E&M systems. The MTRC took over responsibility for maintaining the systems following contract completion on the Airport Railway. On TKE, on the other hand, all E&M contracts, excepting the power supply system contract, stipulate that the contractors are responsible for the maintenance of the system for the first year after completion, with an option for continuing to provide maintenance services after that.
May and June are critical months which will see the commencement of trackside E&M installation works. To ensure progress is maintained and achieve better coordination of the many E&M works to be carried out, the MTRC is providing a fleet of 29 dedicated wagons and 15 locomotives for use by the E&M contractors. Two types of wagons are being provided: flat wagons, for delivery of trackside equipment and for use as working platforms to support high-level installation works; and well wagons for carrying large cable drums.
Organising the work trains is a complex task for which no software has yet proved adequate. Usually stabled at a temporary depot when not required, the works trains will run between the existing, operational network and the new, not-yet energised extension, which is referred to as "defined areas".
As the new E&M systems will rely more on software control than hard wiring, software testing is a major part of the project. In addition to the standard factory acceptance tests (FATs), all systems will be interconnected for integrated software testing prior to their installation on site, to forestall interface problems.
Testing for the railway systems will be carried out in the spring of 2002.
Passengers would probably not notice, but TKE will be the first MTR line to run trains featuring stainless steel body shells.
Not that the client made a conscious decision to switch from aluminium train cars to stainless steel ones.
According to Jeff Hooley, the MTRC's project manager (rolling stock and signalling), the corporation did not specify the type of body shell it wanted for the rolling stock.
"We left it to the free market to determine which type of body shell to be supplied. We wanted to give more tenderers an opportunity to bid for the contract," he said.
In the event, the Europeans who had previously supplied trains with aluminium bodies to the MTRC lost out to a Japanese-Korean joint venture, Mitsubish-KOROS, which won the HK$900 million contract to supply 13 eight-car trains for the extension.
The corporation did specify the use of sliding plug doors, however, because their improved seals make the interior quieter than sliding doors. Another feature which will cut down on the noise generated by the trains is the nomex honeycomb panels on the walls, doorways and end cupboards which are used to create a modern fire resistant interior. This nomex technology is used in aircraft.
Other noise mitigating features include a fully floating floor which sits on rubber cushions that absorb the noise generated by the train-track interface. According to Mr Hooley, a floor slab was tested in an anechoic chamber in South Korea, to determine the optimum floor sandwich. Isolated slab track will complement the train design, ensuring a noise limit of 78 dB will not be exceeded.
Air-conditioning also generates a lot of noise, but how can one keep it down without reducing the amount of cooling provided within trains? In answering this question, the MTRC was helped by observations from the Airport Railway and existing urban lines. What it found was that, while both the Airport Express and the urban lines were cooled to 25 deg C, passengers actually felt cooler on the urban trains due to the air flow generated by fans at the end of the trains. By contrast, the air-conditioning on Airport Express trains has to be turned up to maintain the same degree of perceived coolness because the cars are completely sealed with interior car-end doors.
The answer therefore is to use fans to create a high air flow rate, to produce that apparent feeling of coolness whilst taking care of duct design to minimise the noise generated by the air-conditioning.
A hi-tech cathedral jig suitable for producing the tight shell tolerances necessary for the nomex interior panels is being used in Korea to build the train bodies. The first set of body shells has been completed and is expected to be rolled out onto the test track around May.
Mr Hooley said more tests than ever before would be carried out on the rolling stock.
"We insisted the supplier had a suitable test track of 5 km length where the rolling stock could be run at full speed over a realistic distance," he said. "The first train would be tested over 10,000 km, which is equal to one month's mileage in service. If problems arise we can then institute modifications to the subsequent stock as needed, before they arrive here."
Although the car bodies are built in Korea, manufacture of the trains is actually quite a multinational affair. The front doors, for example, are being manufactured in Spain; the sliding plug doors are being made in Australia; the brake system in Germany; the bogies in the UK and frames in Portugal.
The MTRC runs an office in the UK that handles inspection in Europe, which makes sense as so many parts are being made there. It eliminates the need for long distance travel and also makes it easier to set up meetings where all parties can be brought together to discuss interface issues.
Previous experience has shown that while individual equipment may work well individually, problems often occur when they have to work together as intended. To forestall this problem, the signalling contractor, Siemens Matra, has been asked to install his equipment in Korea for integrated testing.
The German-French joint venture is supplying three systems for the extension: the signalling interlocking which prevents trains from moving onto wrongly set points; the automatic train control system which uses an operation, maintenance and driving aid system called SACEM; and the automatic train supervisory system (ATSS) that runs the timetable governing when which train is to start from which station at what interval. The Germans are supplying the interlocking while the French are responsible for supplying SACEM and the supervisory system.
According to Mr Hooley, the SACEM system was originally developed for a mass transit line in France out of designs developed separately by Siemens, Alsthom and CSEE. The three systems have evolved differently. When the MTRC decided to use the SACEM system in Hong Kong, the three original manufacturers were invited to conduct studies into the feasibility of retro-engineering the system to make it compatible with the existing MTR system.
The studies confirmed the feasibility of doing so and a competition was held. Siemens won and with it the challenge of designing a system which would be compatible with the trackside equipment provided by Alsthom. An interesting difference between the systems of the two manufacturers is the fact that Alsthom tends to install more equipment in the stations than trackside; Siemens is the other way round. The SACEM principle used, however, is the same.
Since it is so critical to the operation of the railway, the testing and commissioning of the signalling system would be a drawn-out exercise involving extensive point-to-point, static, dynamic and variance tests. Mr Hooley said the trains would be put on the Kwun Tong Line to get as much testing and reliability proving done as possible before they are transferred to TKE.
The biggest challenge would be the ATSS, since the timetable can only be tested when the whole network is running. An emulator, after all, cannot duplicate everything that would happen in real life.
Trains on TKE will run at 128 sec headway. Since platform size precludes the addition of extra cars when more capacity is needed, this would be catered for by increased frequency of service to the 105 sec design limit.
Mr Hooley said the TKE trains will have the same seats, colour scheme and information display as the existing fleet, although they will feature a slightly different ceiling design. Few passengers would be aware of the structural difference, and why should they be, as long as there is a draught to keep them cool?
The concept has been around for more than ten years, although if one was to mention partnering in the context of Hong Kong's construction industry two years ago, one would just get a blank stare if not a laugh of derision.
Now it has become a buzzword.
The MTRC must be given credit for proactively promoting the trend, although the Hospital Authority were probably the first client in Hong Kong to adopt the concept. As an employer with a multi-billion dollar project under development, the MTRC has the clout to introduce an initiative which, at the time construction of TKE began, in 1988/99, was completely alien to the adversarial culture of the industry.
Partnering is a generic term adopted by the MTRC that describes a structured means for organisations to establish mutually advantageous working relationships. In order to reap the benefits of the approach, the parties involved must reach agreement on their common objectives, establish a method for problem resolution and work together on continuous improvement.
Partnering has been used by the oil industry and various sectors of the construction industry in Australia, UK and the US since the 1980s. The MTRC looked into the possibility of introducing partnering to its Project Division just before construction of TKE was due to start in 1998.
Although the corporation was prepared to commit to the concept and work on gradual improvements over time, it was not sure how the local construction industry would respond, given the multicultural nature of the industry; the general lack of trust; contract conditions that commonly place too much risk on contractors; and the sub-contracting system.
Having taken these factors into consideration, the MTRC decided to adopt a step-by-step approach, having first of all defined what its concept is about.
The first step was to get the corporation's own staff to embrace the concept, and internal workshops targeting executive and middle management were organised.
The first of the civil contracts on TKE had been awarded in late 1998. In early 1999 a decision was taken to introduce partnering to interested contractors on a non-contractual basis. A partnering consultant was engaged to help with the strategic planning and provide facilitation services. The favourable response elicited by executive-level workshops held with the contractors prompted the MTRC to take another step by holding contract-specific partnering workshops with the following objectives:
* Establishing an understanding of cooperative working relationships
* Setting out and agreeing on mutual objectives
* Agreeing on a process for dispute resolution
* Agreeing on a mechanism for performance appraisal
* Outlining specific joint tasks and identifying action teams
Workshops were held, initially to acquaint participants with the concept and later to review each project according to the established objectives. The initiative is managed by two groups within the MTRC: a steering group responsible for determining the policy and strategic direction; and a project management group responsible for driving and managing the actual process.
Monthly meetings are held on each contract and a partnering performance monitoring system is used so that progress can be gauged and critical issues identified. Staff from the MTRC and the contractors work together on equal terms in exploring ways to improve efficiency, minimise waste and reduce cost. Contractors are encouraged to cooperate with the MTRC and with each other, or simply to share their experiences.
MTRC's concept of partnering
To foster a partnering spirit, social events and functions which transcend the traditional hierarchies and cross-contract barriers are organised, with the cost shared among the parties.
When partnering was initially introduced, the emphasis was on the soft issues or people side of the business. By the end of 2000, however, the concept had already progressed to the commercial side with the signing of five incentivisation agreements with pain-share gain-share arrangements.
It is hard to put a figure on the amount of money saved through the partnering initiative, but significant improvements have been achieved as compared with the Airport Railway. Claims are an accepted part of the MTRC risk-sharing form of contract. On TKE, when claims do arise, they are dealt with in a speedier, more open manner. With still well over a year and a half to the opening of the extension, 85% of the claims notified to date have already been settled; out of a total of 34 contracts, claims remain to be resolved on only four.
Other tangible benefits can also be attributed to the adoption of partnering. For example, with people talking to each other more and relying less on writing impersonal notes, both communication and understanding have improved. The result is shorter response times, quicker approvals and high approval rates, which add to significant time savings.
One particular success story is the depot piling works contracts, which were not only completed ahead of schedule; the final account was signed within days of the last pile's installation at a sum less than the tender price, with both parties happy at the outcome.
Because its success is so dependent on the soft side of the business, it is not surprising that the contracts which have benefited most from partnering are those involving contractors who are keen to embrace the concept, and that less success is recorded on contracts carried out by those who are not as willing to welcome it. However, it is worth noting that even those who do not embrace the concept agree that it has made their job better and contributed towards cost savings.
The MTRC will continue to introduce partnering to future projects, improving its application by drawing on the lessons learnt from TKE.
The CIRC report recommends wider adoption of partnering, to encourage everyone involved in a project to work as a team with shared project objectives. In fact, the industry, abuzz with the concept, is already moving in that direction, although it will take a while before successful models can be developed for the many different types of construction projects carried out in Hong Kong.