-on target for March 31 deadline
The new Demerara Harbour Bridge has sound structural integrity that will not be compromised during its 100-year lifetime and can withstand collision impacts from large vessels, the Ministry of Public Works yesterday assured.
Now nearly 70 per cent completed and on target for its March 31 deadline completion date, Minister of Public Works, Juan Edghill, said that safety and structural integrity were key in designing the structure which is being built to accommodate the free passage of large cargo ships, as it is 50 metres high and 300 meters wide, and even in the unlikelihood of an earthquake here, it will still stand.
“Even though we don’t anticipate an earthquake, in the design, the bridge is built to deal with an earthquake situation,” Edghill yesterday informed reporters during an onsite visit of the facility.
“We can’t design the bridge to prevent the vessels from colliding with it but what we can do is if they collide, minimise the impact on the bridge. What we have done is design for a handymax [vessel], that means it is 48 metres [high] and we provided 50 metres for safety. They need about 100 metres of width to safely passage through the bridge [and] we gave them 300. All those are elements to minimise any collision as they transit the bridge,” Ministry of Public Works Project Manager, Patrick Thompson added.
He said that much planning was done in the design to assure commuters that their safety is assured.
“We have also built the structure of the foundation and the piers for the main tower to resist the collision of a Handymax vessel so if it does collide, the structure is strong enough to not collapse or to not be impacted in any big way,” he said.
In addition, Thompson said that there will also “have some collision protection.” “The foundation works for the tower; those piles that you are seeing are embedded about 120 metres into the river and there are 58 of them supporting each side of the tower so even the foundation is over-designed to ensure that there is no possibility of effects or impacts with collision of the bridge.
On preparation for an earthquake, he also pointed out, “I think the greatest risk to the bridge is in conditions like earthquake conditions and the good thing is that Guyana is out of a seismic zone so while it was designed for earthquake effects, we’re not in any high risk of collapse resulting from earthquake forces,”
There is no worry about smaller vessels traversing the river either as Edghill pointed out, “There is enough room between any of the piers for small speedboats to pass.”
The bridge when completed, will be higher than the Marriott Hotel but with its degree of inclination staggered as it ends at Nandy Park on the east side and La Grange on the west side.
Approach roads which meet the abutment of the bridge and which will be 50 feet on eastern side and “a bit more than 100 feet” on the western part, are also being constructed by the company.
“The abutments of the bridge they have already created there and 50 metres of approach road, because in the contract, it says they have to do 50 meters. The GoG [Government of Guyana] comes in and takes that road to the others. On the east side, that road will go all the way to connect with Heroes Highway. You are coming off the bridge, you come down in the gradient and then you connect to Heroes Highway and you have all the other options to come back to the east bank and that is why we built all these connectors. You have connector roads at Bagotstown, at what is called Red Road, Providence, you have a connector to Greenfield and to Mocha. Getting back to the main road or getting to the bridge,” Edghill explained.
“On the west side, for practical purposes it will be more than 50 metres as it will connect to the roundabout and other roads,” he added.
Acting Project Lead, Tritan Verteniku, explained that Guyana did not have the laboratories needed to conduct some of the structural tests needed as the labs here were not internationally certified. As such, some of the tests were sent to the USA and verified.
Project Quality Management Supervisor, Vittorio Nascetti, added that teams from the company also went to China to inspect the making and quality of materials that would be shipped here for the project.
In July of this year, government advertised for contractors to build the four-lane approach road on the East Bank of Demerara to the bridge. The delivery or construction period has been set to seven months for each lot and contractors were allowed to bid for one or all six of the lots.
The seven-month period would coincide with government’s completion date for the bridge.
When Edghill had updated in May on the bridge, he told this newspaper that it was at 43.7 per cent completion. He said that work was ongoing simultaneously on the east and west sides with foundation works for the beams currently in progress.
The temporary structure was completed since early this year and the minister had told reporters on January 5, “Based on my inspection and the reports I have received today from the contractor, 100 per cent of the temporary structure is completed, which I am happy for. And they are now putting in the platforms, which are required…”
Then, he had also detailed that that the main tower, would link the 300-metre span from the western side to the eastern side of the bridge. Each of the towers will be supported by 38 steel piles. Further, each of the steel piles will require approximately 500 cubic metres of concrete.
“From the technical explanation in layman’s terms, this is about 58 trucks of concrete the contractors will be using. Note, these are ready-mix trucks, and from what the contractor is telling me, one of those piles and the concrete that is used is sufficient to build a three-storey house in Guyana…,” he elaborated.
Edghill said that the landmark pouring of concrete that was done on December 5, 2023, saw work on the eastern side where eight of those piles were completed.
He said too that the bridge was being constructed in compliance with international engineering standards.
Engineers and acting project lead for Polytechnica -the consultancy firm that is overlooking the infrastructural development to ensure excellence – were also on site yesterday and reported that except for setbacks with testing during early testing periods, there were no challenges currently.
The project engineer alongside another employee at the Ministry of Public Works and a consultant from Polytechnica, had travelled to China back in November/December of last year for two weeks to inspect all facilities where the materials are being fabricated before shipment, Edghill had said.
Yesterday the Minister said that it was at 67.8 percent and that the contractors and team, “work day and night to bring us to this stage.”
Providing a breakdown in works done by percentage, China Railway Structural Engineer, Ganesh Persaud, said that as at yesterday morning, the 67.8 per cent completed included driving 495 of the 658 piles, the construction of 39 metres of the 112-metre tower legs, 50 per cent of the east and west approach piers, and 100 per cent completion of the east and west retaining walls.
The abutment (P0 and P62) has been fully completed along with the east and west retaining walls. The east approach road is 35 per cent completed while on the west side this has not yet began as the focus is to complete the eastern section first.
The tie beam or main tower cross beam as it is called, is now at 12 per cent but is being worked on continually. Cables for the tie beam have a 60-year lifespan and will need maintenance works as is required.
And while the main and side span on the bridge is listed as zero per cent completed along with precast girders at three of 208 and one of 264 respectively, the project team explained that some of the materials for the works had been completed but not yet arrived in the country due to shipping delays.
The 2.6-kilometre crossing being built by China Railway Construction Corporation (International) Ltd in a joint venture with China Railway Construction (Caribbean) Company Ltd and China Railway Construction Bridge Engineering Bureau Group Company Ltd, will link Nandy Park on the East Bank Demerara with La Grange on the West Bank Demerara. It will have four lanes, with a total width of 23.6 metres including the median and the shoulders, providing sufficient room for safe and effective traffic flow.
Of the 371 people employed to work on the project, 180 are Chinese, 98 Guyanese, 85 Venezuelans, one Cuban, five Trinidadians and two Nigerians. Notably 90 of the 371 are indirect, and 281 are direct labour.
