BSP hammers the point home at able seaton port
A new BSP International Foundations piling hammer is playing an important role in the resurrection of the massive Able Seaton Port on the River Tees at Hartlepool in County Durham. Now owned by Able UK the company, which bought the dock in 1996, is using the heavy-duty hammer, a CG210 along with a HH357, to drive the steel piles needed to close-off the dry-dock which will be drawn out and re-driven when a ship or oil platform needs to enter or leave the dock.
Able UK is primarily a breaker of marine structures, ships, and redundant oil platforms on the site and is also a licensed waste disposal contractor. The ship-breaking is a fairly complicated and time consuming task and needs to carried out safely and in an environmentally-friendly way. In Able UK’s case it involves substantial marine civil engineering works to meet these criteria. Reckoned to be the largest of its kind in the world, the 10 hectare (25 acres) dock can accommodate ships up to 366m long with no limit in width.
When Laing Offshore left the site back in 1990 the massive dry-dock gates had collapsed which required very expensive refurbishment or replacement costing in the region of several million pounds. The gates need to be in excellent working order if the dry dock has to be emptied and of course to keep the River Tees out. At the moment Able UK is closing-off the dry-dock using steel piles but eventually new dock gates will be fitted in the future but for now the short-term practical fix is ongoing.
Following the decision by Hartlepool Borough Council to finally grant planning permission in November 2007 piling began early this year (2008). The work being undertaken by the BSP piling hammers involves driving more than 1,000 steel tubular piles, some of them to depths of 30m. Pile diameters vary from 660mm to 1,067mm and the largest at 1,420mm which are also the longest at 30m. Local ground conditions are firm and comprise stiff clays with the final three metres being rock, requiring a 1,350mm socket to be cored. The very hard driving conditions present quite a task for the BSP hammers but the company expects the piling phase to be completed in November.
In addition to sealing off the entrance to the dock, Able UK is using the hammers for foundation piling to construct a 308 metre-long quay capable of being loaded to 40t/m2 and designed to be dredged to -15m CD. Both will be used in ship/structure-breaking and for the building of an oil/gas exploration platform by a contractor who will occupy the facility on a long term basis. Time is of the essence because a number of ships and oil platforms are booked to enter the yard and structures of this size and unwieldiness have to be organised to a strict programme.
Prior to ordering the CG210 hammer Able UK looked at its programme of works, consulted with some large civil engineering contractors but in the end the decision was to construct the works in-house. To do that a major investment was needed in order to purchase some specialised and expensive construction equipment.
Special Project - Manager, Andrew Jacques says: “Initially we thought about hiring-in all of the equipment, crawler cranes, piling hammers, in fact the whole shooting match. However, when we looked at delivery and waiting times, logistical uncertainties and the length of our construction programme as well as the possibility of future works, the decision to buy became more and more logical.
“Our first purchases were two large Sennebogen crawler cranes from EH Hassell, the UK distributor and then we had to decide on a couple of piling hammers.”
Although Mr Jacques was fully involved in all of the purchase decisions, he says the selection of the piling hammers was left to Mark Patterson, the site construction manager. “We looked at lots of hammers,” says Mr Patterson. “But in the end the decision was quite straightforward as the BSP product stood head and shoulders above the rest so far as performance was concerned. Add in a reasonable pricing structure, a good delivery schedule and the decision was taken.”
The BSP product scores well because it has a high efficiency hydraulic cylinder that gives significantly improved performance. Compared to other hammers, the energy that is transmitted from the hammer to the pile is greater. This results in fewer blows per pile required and therefore the job gets done quicker,” he adds.
“We have chosen to operate the hammer in its base mode of 14t but if we wished to we can change the configuration of the hammer to deliver 20t with only minor works and modification. It has a relatively uncomplicated, simple to adjust framework. The shroud is robust which also makes location on the piles straightforward. And significantly, the ram is only held at one end which makes driving raking piles much simpler.
It came with a good toolkit and a great selection of raking chains and eyes, all of which help in getting the job done. The control box is simple to operate and, importantly, it is waterproof which is a bonus,” he explains
“If required we would probably buy another BSP rig,” he adds.
The CG210 is just one of BSP’s heavy-duty CG range of piling hammers offering ram weights from 12t up to 20t and maximum impact energies extending from 185kNm to 300kNm. All have been designed for driving a variety of bearing piles including steel, combi piles, ‘H’ sections and reinforced/pre-stressed concrete piles and can be operated from piling rig leaders or crane suspended.
Some important features include: total control of hammer stroke and blow rate, precise matching of energy to suit the particular pile driving requirements and the ability to drive piles with an ultimate load bearing up to 14,500kN.
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