Extending the working life of escalators whilst still maintaining 'business as usual'
Background
Straddling the railway tunnels leading from Liverpool Street station, Exchange House’s architecture borrows more from bridge construction technology than conventional piling and steel frame design. Our involvement with British Land property on Broadgate extends back to 2012 with Exchange House the prominent building on Exchange Square in the heart of The Broadgate Estate.
The building is served by a group of eight passenger lifts in the core plus dedicated goods and firefighting lifts. The tenants occupying the lower floors are also served by a bank of escalators which allows access to client suites and conferencing areas.
Brief
We have a long relationship working with Exchange House’s management team including planning and implementing a lifecycle modernisation scheme for all but the main passenger group. These projects are commissioned on a turn-key basis whereby we design, procure and manage the modernisation including duties of Principal Designer under CDM.
When it came to extending the working life of the escalators we looked at the feasibility of outright replacement, in truss replacement and modernisation.
Challenges
The structure of the building and the escalator access to the occupiers floors and possibility of severe disruption presented a unique set of considerations.
Process
We determined that modernisation would deliver all of the features of a new installation whilst retaining the heavy duty truss steel structure. Furthermore, the difficulties of delivering, accessing the building and lifting into place new escalators were to be avoided.
We still had to overcome the challenges of maintaining escalator access to the occupiers floors whilst segregating the works for safety, noise and visual impact. This was achieved through an innovative lightweight curtain hoarding. We not only extended the escalators life embracing current safety features but also achieved 20% savings in annual energy consumption.
Outcome
The lifts, escalators and cradles at Exchange House benefit from our regular structured maintenance quality audits. We have applied this dynamically in response to changing requirements.
One of the drivers altering our quality auditing provision was the findings from our suite of condition evaluation techniques including drive profiling and bearing monitoring. These also led to component replacement where they exhibited signs of imminent failure. Fix before failure prevents extended downtime, secondary equipment damage and potential trapped passengers.
Our understanding of the building and our breadth of service offering allowed us to investigate and diagnose an increase in waiting times experienced by passengers using the main group of lifts. The solution we identified entailed a mix of: improved passenger information, optimising adjustment and investment in higher performing doors. This intelligent analysis and solution finding resolved what could have been a fundamental and expensive change to the lift group.
