Dock traffic lights are red and green signals mounted outside and inside a loading bay to tell the driver and dock staff when it is safe to move or load. Interlocks are control links that stop equipment operating out of sequence, for example preventing the door opening until the trailer is restrained, or the leveller operating until the door is fully open.
Why do sites in Gloucestershire choose this?
If a site in Gloucestershire has had door panels damaged by levellers raised too early, a leveller-to-door interlock is a straightforward fix to consider. New warehouses in Gloucestershire can have lights and interlocks wired in during the electrical fit-out, avoiding retrofit cabling and keeping every bay on one control standard.
Sites around Gloucestershire that run night shifts often find traffic lights easier for drivers to read than staff waving or knocking on the cab door.
Any project involving dock traffic lights and interlocks at a working site in Gloucestershire takes planning. We survey free of charge, quote a fixed price in writing, and then agree a programme that keeps as much of the dock running as possible. Specialist installation engineers carry out the work under our management, out of hours if that suits you better. On completion we test each item, show your team how it operates and leave the documentation with you.
Which interlocks should a loading bay have?
The most useful loading bay interlocks stop the door opening until the trailer is in place or restrained, and stop the leveller operating until the door is fully open. Beyond that, the right set depends on the equipment fitted and your risk assessment.
- Door to restraint: the door cannot open until the restraint is engaged or a trailer is detected.
- Leveller to door: the leveller cannot be raised until the door is fully open, which prevents the lip hitting door panels.
- Door to leveller: the door cannot close until the leveller is back in its parked position.
- Restraint release: the restraint only releases once the door is closed and the leveller parked.
- Shelter to trailer: an inflatable shelter only inflates when a trailer is docked.
On a bay without a restraint, a trailer presence sensor can take its place in the door logic, although it confirms a trailer is there rather than holding it. Combining interlocks with vehicle restraints gives the strongest protection against drive-away.
What happens on site when traffic lights and interlocks are fitted?
Fitting lights and interlocks is mainly electrical work, and each bay is out of use while its controls are connected and tested. Working bay by bay keeps the rest of the dock running.
- Fix the signals: the outside light is mounted on brackets at a height drivers can see, and the inside light beside the door.
- Run the cables: wiring is run in conduit or trunking between lights, sensors and control panels.
- Isolate and connect: the door and leveller supplies are isolated and locked off while the interlock wiring is connected, or a new bay panel is fitted.
- Test every sequence: each interlock is tested, including what happens if a step is attempted out of order.
- Brief staff: dock staff are shown the new sequence, and signs are fitted for drivers.
It helps if you can provide any electrical drawings for the dock, access to the distribution board, a person who can authorise isolations and an agreed order for releasing bays.
Towns we cover in Gloucestershire
Find your town in the list below for details of dock traffic lights and interlocks across Gloucestershire, or contact us if your location is not shown.
Budget range for supply and fit. The written quote after a free survey is the fixed price. All guide prices.
Which rules apply in England?
Workplace safety in England is regulated by HSE. For a loading bay in Gloucestershire, that means doors meeting regulation 18 of the Workplace (Health, Safety and Welfare) Regulations 1992, equipment maintained under PUWER and suitable safeguards against vehicles driving away too early. We check what applies at survey and design the bay accordingly.
Questions
Which building and safety rules apply to a site in Gloucestershire?
It depends on which UK nation the site is in. England and Wales use Building Regulations approval, Scotland uses building warrants and Northern Ireland uses building control approval from the council. Workplace safety is regulated by HSE in Great Britain and HSENI in Northern Ireland, and energy rules differ between nations. For your site in Gloucestershire, we check what applies at survey and design to it.
How long does installation take at a site in Gloucestershire?
It depends on the equipment, the number of bays, the condition of the dock and whether any building or electrical work is needed. We agree a programme with you after the survey, setting out which bays are out of use and when. Larger jobs are usually phased so that part of the dock stays open, and out-of-hours working can be arranged.
Can you add lights and interlocks across a whole dock in one project?
Yes. A whole-dock project is usually phased bay by bay so most doors stay in use, and every bay ends up on the same control standard. That consistency makes training easier for staff and drivers, and it simplifies servicing because every bay behaves in the same way.
Can interlocks be fitted to a manual loading bay door?
Yes. A door position switch fitted to a manual door can confirm when it is fully open or fully closed. That signal lets the traffic lights change automatically and stops the leveller being raised until the door is out of the way.
Other services in Gloucestershire
Full guide to dock traffic lights and interlocks · All loading bay services in Gloucestershire

