- Location
- Sudbury, Suffolk
- Main postcode district
- CO10
- Nearby (straight line)
- Colchester (13 miles), Haverhill (13 miles) and Braintree (13 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.
Why do sites in Sudbury choose this?
Sites around Sudbury that run night shifts often find traffic lights easier for drivers to read than staff waving or knocking on the cab door. If a site in Sudbury has had door panels damaged by levellers raised too early, a leveller-to-door interlock is a straightforward fix to consider.
Whether your unit in Sudbury has one dock or twenty, the survey looks at each bay's existing controls before we quote a fixed price in writing.
For dock traffic lights and interlocks in Sudbury, we begin with a free site survey and a fixed written quote, so you know the scope and cost before committing. We take responsibility for managing the job, and specialist installation engineers carry it out under our supervision. Bays are taken out of use in a planned sequence so the rest of the dock keeps working, and evening or weekend work can be arranged. Each item is tested at handover and the documentation is left with you.
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.
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.
The same published guide range applies across England; access, out-of-hours working and site conditions are confirmed at the free survey.
Survey checklist for your dock
- Gaps around trailers where heated or chilled air escapes
- Age and condition of the equipment already in place
- Whether planning, building control or a building warrant may be needed
- Yard gradient and the slope of the approach to the dock
- Asbestos register and any other site hazard information
- Forklift and pallet truck loads crossing the leveller platform
Options to discuss
Standalone LED traffic lights
A red and green pair for each bay, one outside for the driver and one inside for dock staff, switched manually from a control beside the door.
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.
Which rules apply in England?
Sites in Sudbury fall under the rules for England. Structural changes such as forming a new opening or a dock leveller pit may need Building Regulations approval, and external structures such as loading houses, canopies or new dock approaches can need planning permission from the local planning authority. We check what applies at survey and build any approvals into the plan.
Questions about dock traffic lights and interlocks in Sudbury
Will you deal with building control and planning for a project in Sudbury?
We check at survey whether the work is likely to need approval. Forming a new opening or dock pit may need Building Regulations approval, a building warrant or building control approval, depending on the nation, and external structures such as loading houses can need planning permission. Where approval is needed, we explain what is involved, work with your designer or agent, and build it into the programme.
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 Suffolk 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.
Do you remove and dispose of the old equipment?
Yes, where it is part of the scope. When we replace doors, levellers, shelters or seals at a site in Sudbury, removal and disposal of the old equipment can be included and is itemised in the quote, so it is clear what is covered. If anything should be kept, such as a frame or motor that is still serviceable, we agree that at survey.
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.
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.
Dock traffic lights and interlocks near Sudbury
If your site is not in Sudbury itself, it may be near one of these: Colchester (13 miles), Haverhill (13 miles) and Braintree (13 miles). Pick the closest.
Other loading bay services in Sudbury
Full guide to dock traffic lights and interlocks · Everything we do in Sudbury
Call us or request a quote online to talk through loading bay work at your site in Sudbury.