FPT Fluid Power Technology hollow jacks

Jacking the largest TBM (tunnel boring machine) in the UK for the for the Silvertown Tunnel
Cilindri idraulici forati FPT Fluid Power Technology


FPT Fluid Power Technology hollow jacks


United Kingdom



FPT Fluid Power Technology has manufactured and supplied the hollow jacks used for the jacking of the largest TBM (tunnel boring machine) in the UK via the flying launch method, for the Silvertown Tunnel. A tunnel under the Thames linking Silvertown to the Greenwich Peninsula in east London.

The completion of the first launch has been carry on by PHL HYDRAULICS UK LTD, our partner for the UK market specialised on bridge jacking and lifting – lowering operations.
The120t Thrust Ring was positioned, and the hydraulic equipment mounted. The Thrust Ring is a vital component for the TBM Flying Launch system. The 12m diameter machine will be jacked forward into position utilising 260t hollow jacks, and a dedicated pump.

The diameter of the TBM measures 11.91m which is the equivalent of almost three double decker buses. Compared to the TBMs used on the Crossrail project (7.1m), the Northern line extension (6.03m) and Thames Tideway project (8.85m), this machine dwarfs’ other similar plant to have been operated in the UK in recent years. It will also be larger in diameter than those working on the delivery of High Speed 2. The length of the TBM is approximately 82 metres, and it weighs 1,800 tonnes – 1200 tonnes of that being the enormous shield which equals 95 times the weight of a double decker bus. The heaviest Crossrail TBM shield weighed in at 526tonnes, Northern Line Extension at 310tonnes and Tideway at 780tonnes.

TBM of 11.9 OD was launched from shaft via ‘Flying Launch’ method of hydraulic jacking this is the second time this method has been used in the Uk with crossrail been the first. The TBM has been launched forward for 12mts to allow the TBM mine the ground before its own rings were installed & it’s thrust system took over & its own cylinders are used. A thrust ring at back of TBM, connected to a fixed frame at the tunnel portal by a series of high tensile bars. On the top of the frame and on the bottom have been used hollow hydraulic cylinders. FPT Fluid Power Technology have manufactured and supplied the 260 ton hollow jacks. Hollow centre jacks locked off on each bar, then hydraulically energised, pulling the TBM forward.