Project Engineering

Inchinnan Roll Back Bascule Bridge

Contact: James Crawford

Type of Project

Mechanical
Electrical
Machinery

Outline of Project

Inchinnan bridge has been in regular use for half a century. About the same time as it obtained listed structure status it became apparent that major examination of the machinery was necessary to pre-empt mechanical or electrical failure.

Cadogan Consultants was asked to report on its condition and make recommendations for its continued use whilst retaining the original method of operation.  Following a report and recommendations a full restoration project on the machinery was instructed by Renfrew Council.

The substantial structure carries traffic on the A8 and is untethered to either abutment. To open for river traffic it rolls one quarter of a circle assisted by the counterweight which can be seen above the carriageway when in the normal position.

Its opening and closing motion is controlled by pinion gears acting on racks attached to the underside of two actuation beams.  Two 50HP slip ring induction motors provide the motive power.  Its slate insulated electric control panel must be one of very few of this type still to be in operation.

It is believed the moving structure will be capable, if required, of continuing in operation for a further half century.

key skills used by cadogan consultants

• Mechanical Engineering
• Electrical Engineering
• Project Management
• Knowledge of older types of M & E Plant
• Electro hydraulics (for new inconspicuous nose bolt for extra safety)