- Location
- Trowbridge, Wiltshire
- Main postcode district
- BA14
- Nearby (straight line)
- Westbury (4 miles), Melksham (5 miles) and Bath (8 miles)
- Survey and quote
- Free, with a fixed written quote
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.
What should sites in Trowbridge consider?
New warehouses in Trowbridge can have lights and interlocks wired in during the electrical fit-out, avoiding retrofit cabling and keeping every bay on one control standard. Whether your unit in Trowbridge has one dock or twenty, the survey looks at each bay's existing controls before we quote a fixed price in writing.
Distribution centres near Trowbridge taking trailers from many different hauliers benefit from a signal every driver understands, regardless of language or familiarity with the site.
Your loading bay stays our responsibility from the survey to the handover. In Trowbridge, the survey and written quote are free, and the quoted price is fixed for the agreed scope. Installation is carried out by specialist engineers working under our management, at times planned with you to protect your loading schedule. Out-of-hours work is available by arrangement. We finish by testing the equipment and handing over its documentation.
How do inside and outside dock traffic lights work together?
Inside and outside dock lights always show opposite colours: when the driver sees red, dock staff see green, and the other way round. Each light is aimed at a different person, so each one only ever gives one instruction.
- Outside light, facing the driver: red means stay on the bay because loading is in progress; green means the bay is clear to leave or to reverse on to.
- Inside light, facing dock staff: green means the trailer is in place and it is safe to open the door and load; red means do not open the door or enter the trailer.
Lights can be switched in three main ways:
- Manually, by a switch beside the door, relying on dock staff to change it at the right moment.
- By door position, so opening the door automatically turns the outside light red.
- By the restraint, so the light only changes when the trailer is physically held.
Can traffic lights and interlocks be added to older loading bays?
Yes, traffic lights and interlocks can be added to most older loading bays, although some need new control panels before the interlocks can work.
- Manual doors: a door position switch can confirm the door is fully open or closed, which lets lights and leveller interlocks work even without a motor.
- Older powered doors and levellers: basic control boxes may not have connections for interlocks, so a combined bay panel can replace separate controls.
- Mixed equipment: doors and levellers from different suppliers can usually be brought under one interlock panel, so every bay works the same way.
Interlocks cannot make faulty equipment safe. If a door or leveller has a defect, it should be repaired before interlocks are added, and the survey will flag anything we find. Upgrading lights and interlocks at the same time as replacing a door or leveller is often the most economical moment to do it.
The same published guide range applies across England; access, out-of-hours working and site conditions are confirmed at the free survey.
What do we check at the survey?
- Yard gradient and the slope of the approach to the dock
- Wall and steel structure for door, shelter and bumper fixings
- Asbestos register and any other site hazard information
- Temperature requirements for chilled, frozen or ambient goods
- Lighting inside trailers and at the dock face
- Gaps around trailers where heated or chilled air escapes
Options to discuss
Door-linked lights
Lights that change automatically with the door position, using a door switch or a signal from the door control panel, so the outside light turns red as the door opens.
Full bay interlock panel
A single control panel that runs the door, leveller, restraint and shelter in the correct sequence, with indicators showing which step is active or blocked.
Regulations and approvals in England
Powered doors and dock equipment installed in England may carry the UKCA or the CE mark, and doors are covered by the product standard BS EN 13241. We hand over the relevant documentation for each item fitted in Trowbridge. Planning and Building Regulations questions are never assumed either way: we check what applies at survey, so you know before work is booked.
Questions about dock traffic lights and interlocks in Trowbridge
How long does installation take at a site in Trowbridge?
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.
Is VAT included in your guide prices for dock traffic lights and interlocks?
No. Our customers are businesses, so guide prices exclude VAT, which is added at the standard rate. The same guide range applies in Wiltshire as everywhere else: for dock traffic lights and interlocks, it is £650 to £3,400 per bay, excluding VAT. It covers supply and fit for a typical installation. Your fixed written quote after the free survey shows the net price, the VAT and exactly what is included.
How do you price dock traffic lights and interlocks for a site in Trowbridge?
Guide budgets for supply and fit are £650 to £3,400 per bay, excluding VAT. The figure moves with size, insulation, the operator, electrics, access, any pit or groundworks and out-of-hours working. Where levellers are involved, the guide assumes an existing, sound pit. After the free survey you receive a fixed written quote, and that is the price for the agreed scope.
Do traffic lights and interlocks need maintenance?
Yes. Lights, sensors and interlocks should be checked at each planned service visit, including testing the full sequence and confirming that steps attempted out of order are blocked. As part of the dock equipment they fall under PUWER, which requires work equipment to be maintained in a safe condition.
Which way round do the inside and outside lights work?
The inside and outside lights always show opposite colours. While a trailer is being loaded, the outside light is red so the driver stays put and the inside light is green so staff can work. When loading is finished and the door is closed, the inside light turns red and the outside light turns green for the driver.
Dock traffic lights and interlocks near Trowbridge
If your site is not in Trowbridge itself, it may be near one of these: Westbury (4 miles), Melksham (5 miles) and Bath (8 miles). Pick the closest.
Other loading bay services in Trowbridge
Full guide to dock traffic lights and interlocks · Everything we do in Trowbridge
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