Holdfast Training Services Trial Blog

In keeping with my esteemed colleagues I am joining the post-AER blog party.

The scale of the Crossrail project coupled with the number of stakeholders involved leads to an awful lot of inertia within the organisation. To push a bad nautical analogy the Crossrail oil tanker makes the British Army bureaucracy feel like driving a particularly nippy frigate.

As part of the tunnel ventilation contract ATCjv has to justify the access and maintenance strategy for the end user (Rail for London, the Crossrail arm of TfL). This includes ensuring the designs allow for the replacement of equipment during the 100-year design life of the stations.  I have been attempting to re-write the access and maintenance strategy for a system of dampers installed in a 3 x 3 grid against wall openings at the Paddington Station platform level.

A drawing showing the damper installation – the space available for an access and maintenance crane is shown by the red arrow.

Some similar damper banks installed at Bond Street station

The means of replacement of these damper units was a scope gap in the initial works information for the station contractors. As the stations are running well behind schedule this scope has been moved over to ATCjv on a ‘Cost +’ contract.  This is clearly a lucrative deal for ATCjv that has not incentivised the company to seek a low-cost solution in any way.  The resulting design is for a series of gantry cranes to allow the replacement of the dampers.

Kone gantry crane in Canary Wharf station – similar to that proposed for the damper access and maintenance strategy.

In the case of Paddington station this solution is not suitable for the following reasons:

1. There is no space for the gantry crane on the downstand beam (see drawing detail at top and below).
2. The gantry crane would not be able to access the top of the damper frame to remove it (making the whole installation pointless).
3. It’s a massively expensive solution to a simple problem.

Gantry crane proposed design. Damper units are the pink louvers in the 3 x 3 grid, crane outline is shown in red.  Note the  position of the crane hook is below the top flange of the uppermost damper unit leaving no allowance for slinging the load.

Rather than mess around installing and then maintaining a series of electric cranes I am trying to justify using a portable material lift instead:

Mechanical material lift, kindly modelled by Mr Tom Docker

Here lies the oil-tanker. Getting this solution approved has required meeting with the end user, maintenance staff, station main contractors, crane installers and Crossrail representatives.  The justification has included a feasibility study, cost-benefit analysis and a new access and maintenance strategy.  This process has been ongoing for two months, and will hopefully be concluded before I depart for phase 3.

The scale of commercial manoeuvring and arse-covering has been pretty impressive and has given me some pretty good insights into the importance of writing a tight contract instruction. In this way Crossrail could have maintained focus on a simple and common-sense solution to prevent the problem running away into a taxpayer money-pit.

I am guessing that everyone will have a similar example from their own sites; has anyone been successful in actually putting an issue like this to bed?

Mark