New London bus stops on firm footing
London Transport Buses owns 17500 bus stops in Greater London and is responsible for determining the networks, frequency of services and managing the contracts for over 700 bus routes. As part of its programme to encourage greater use of bus services, London Bus Services has introduced a new bus stop design.
The new stop is a lightweight modular structure in aluminium that can quickly and easily be modified. With the familiar LT Roundel still intact the new design won approval from the Royal Fine Arts Commission and has been exhibited in the London Design Museum.
It was necessary when replacing the old posts to be able to install the foundation on one day and attach the post, flag, timetable etc the next day without disrupting bus services or putting the public at risk.
To achieve this a stainless steel socket was embedded into the foundations. The post plugged into this socket can simply be removed and replaced as and when needed. It was important also that the concrete being used was structurally adequate, durable and easily installed.
London Transport Buses approached CMS Pozament to jointly design concrete that met these requirements. They had also engaged the Advanced Engineering Division of Colebrand Ltd, who played a central role in determining the performance criteria.
This called for concrete with a usable working time of six to ten minutes, that was mixable in a standard mortar mixer, free flowing with a self- compacting ratio of 0.30 w/c and free from harmful additives. It was required that the compressive strength of the concrete at 1 hour would be 8N/mm2 Min, at 24 hours 20N/mm2 Min and by 7 days 30N/mm2 Min.
An agreed quality control procedure was also incorporated into the concrete specification
to ensure performance was continually achieved.
Truefom Installations, a division of Trueform Engineering Ltd, were awarded the new contract and because of the nature of their business they were able to fabricate the bus stops along provision of an installation, maintenance and emergency call out service.
It was a daunting task but with the four parties working together so well to fine tune the practicalities of foundation installation, it is no surprise that the project continues, unabated to the benefit of all concerned.
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