- Decide the number and mix of docks early, balancing levellers against level-access doors, because pit sizes, embedded steel and ducts are cast into the structure.
- Match the door, leveller and shelter or seal to the vehicles you expect, including trailer heights and widths, refrigerated units and any vans or rigid vehicles.
- Specify safety as a system: bumpers, wheel guides, lights, restraints, traffic lights and interlocks designed together with the power supply and controls.
- Coordinate pit dimensions, embedded steel, ducts and power with the main contractor and civils, then plan commissioning, training and O&M handover.
When should the dock package be specified on a new warehouse?
The dock package should be specified at design stage, before the slab and dock walls are detailed, because leveller pits, embedded steel, ducts and openings are built into the structure. Changing them after the concrete is poured is expensive and slow.
Early decisions shape the rest of the build:
- the number, spacing and height of dock openings in the elevation;
- pit dimensions, kerb angles and embedded steel for each leveller;
- ducts and power for doors, levellers, shelters, restraints and controls;
- yard layout, approach gradients, drainage and wheel guide positions;
- the energy performance of the doors as part of the building envelope.
Bringing a loading bay specialist into the design team early helps the structural engineer, architect and civils contractor work to equipment that has actually been selected, rather than a generic allowance.
How many docks do you need, and in what mix?
The number of docks depends on the volume of vehicles you expect, how long each takes to load or unload, your peak periods and how you split inbound and outbound traffic. The mix depends on the vehicles: dock levellers suit articulated trailers and rigid lorries at dock height, while level-access doors suit vans, smaller vehicles and goods moved at ground level.
- Dock levellers: the core of most distribution warehouses, bridging between a dock typically around 1,200 mm above yard level and trailer beds that vary roughly from 900 to 1,600 mm.
- Level-access doors: ground-level doors for vans, forklifts and oversized goods.
- Lift tables: where a dock must serve vans and low vehicles as well as trailers.
- Future capacity: consider forming extra openings or pits now for future docks, which is usually simpler than adding them to a finished building.
Think also about where returns, waste and empty pallets will be handled, as these often need a door of their own. Your operator or logistics adviser usually owns the throughput calculation. We help translate it into a practical dock layout and equipment specification.
Which doors and levellers should you specify?
A common specification for a new distribution warehouse is an insulated sectional door with an electric operator at each dock, paired with a hydraulic swing-lip or telescopic-lip leveller sized to the trailers and loads. The detail depends on the operation.
Doors:
- insulated sectional loading bay doors, with panels typically 40 to 80 mm thick, in openings commonly about 3.0 m wide by 3.0 to 3.5 m high;
- in England, a limiting U-value of 1.3 W/m²K for vehicle access and similar large doors under Approved Document L 2021 Volume 2; the other nations have their own rules, and we confirm the figure for your project;
- cold store doors for chilled and frozen areas, and high-speed doors for busy internal openings;
- safety edges against trapping, and manual operation where it is needed for safety, as the Workplace Regulations set out for powered doors.
Levellers:
- swing-lip levellers, with a lip typically about 400 to 500 mm, for general trailer loading;
- telescopic-lip levellers, with lips commonly extending 500 to 1,000 mm, for end-loading, precise placement or mixed trailers;
- a rated capacity to suit the heaviest trucks and loads crossing the leveller, and a deck length that gives a workable slope across your trailer heights.
BS EN 1398:2009 is the safety standard for dock levellers, and it is currently under review.
Shelters or seals: what suits your fleet?
Choose dock shelters or seals by fleet: retractable shelters suit mixed trailer sizes, foam dock seals suit consistent fleets and give a close seal, and inflatable shelters suit temperature-controlled docks that need a close seal across a range of trailers. Retractable shelters are a common default for mixed traffic, with seals or inflatables where temperature control matters.
- check trailer widths and heights, including refrigerated units and double-deck trailers;
- allow for the projection of the shelter in the yard layout;
- match the shelter to the bumper projection and the leveller lip reach;
- allow power and controls for inflatable shelters.
Our guide to dock shelters vs dock seals compares the options in detail.
What safety equipment should the docks have?
Each dock should have safeguards against vehicles driving away too early, bumpers to protect the building and leveller, and good visibility for drivers and staff. HSE guidance on loading says there must be safeguards against drivers driving away too early, with measures including traffic lights, vehicle or trailer restraints and the person in charge keeping the keys or paperwork until it is safe.
- Vehicle restraints: wheel-based restraints that hold the trailer until it is safe to leave.
- Traffic lights and interlocks: red and green signals for drivers and staff, and interlocks that control the sequence, for example so the door cannot open until the trailer is restrained.
- Bumpers and wheel guides: to protect the dock and centre the trailer.
- Dock lights: swing-arm lights to light the inside of the trailer.
- Leveller guarding: toe guards or skirting where something could be caught.
Designing these as one system at the start is simpler than adding them bay by bay later. See vehicle restraints for the options.
What power and controls does each dock need?
Each dock needs a power supply for the door operator, the leveller's hydraulic power pack, any inflatable shelter fan, dock lights and restraints, plus a control layout that lets staff operate the bay from one position. Agreeing this with the electrical designer early avoids surface-mounted cables and controls being added after handover.
- the supply and isolation for each bay, and where the control panels sit;
- combined control panels for door, leveller, restraint and lights where interlocks are used;
- emergency stops and isolators within reach of the operator;
- external signals for drivers, and any link to building management or yard systems;
- ducts from the controls to restraints, lights and sensors in the yard.
Allow spare ducts and spare capacity in control panels where you may add equipment later, such as restraints or extra sensors, so a future upgrade does not mean breaking out finished surfaces.
What should the yard design allow for at the docks?
The yard in front of the docks should give vehicles room to manoeuvre and reverse square to each door, drain water away from the dock face, and keep people on foot away from reversing vehicles. Decisions on the yard affect how well the dock equipment works every day.
- Approach length and gradient: a level or gently sloping approach, so trailers stand at a predictable height against the dock.
- Dock spacing: enough room between doors for vehicles to reverse in without swinging into the next bay.
- Drainage: channel drains or gullies in front of the dock face, especially where the approach falls towards the building.
- Markings and lighting: bay numbers, guide lines and lighting for night work.
- Pedestrian routes: walkways and crossings kept apart from reversing areas wherever possible.
How do you coordinate the dock package with the main contractor and civils?
Coordinate the dock package by giving the main contractor and civils contractor fixed equipment information early: pit drawings, embedded steel details, ducts, loads and power requirements. The dock specialist then checks the civils work against those details before installation.
- Pit dimensions: length, width and depth for each leveller type, plus drainage in the pit.
- Embedded steel: kerb angles and fixings cast into the pit and dock face, set to the right level and line.
- Ducts: from the pit and dock face to the control positions and yard equipment.
- Openings: structural openings, lintels and fixing zones for doors and shelters.
- Yard: approach gradients, drainage, wheel guide fixings and restraint positions.
- Programme: when the building is weathertight, when power is available and how the dock works fit around other packages.
We work with developers and main contractors, or directly with the end user: we provide drawings and information for the design team, check pits and steel before installation, and manage the installation and commissioning, carried out by specialist engineers under our management. Our complete loading bay installation page explains how a package is put together.
What should be included at commissioning and handover?
At commissioning and handover, every door, leveller, shelter, restraint and control should be tested and the results recorded, and the client should receive operation and maintenance (O&M) information, training for staff and a plan for inspection and servicing. This is the point where the equipment passes from the contractor to the operator.
- commissioning records for each bay, including safety devices and interlocks;
- O&M manuals, drawings, declarations of conformity and marking information, which in Great Britain may be UKCA or CE, and in Northern Ireland CE or CE with UKNI;
- training for operators and supervisors on normal use and what to do if something goes wrong;
- a planned maintenance schedule, and arrangements for inspection under PUWER and, for lift tables, thorough examination under LOLER;
- the manufacturer's warranty details, with workmanship terms set out in writing.
Arrange the first service and inspection dates before handover is signed off, so nothing falls into the gap between contractor and operator. Powered doors are covered by BS EN 13241 as the product standard and BS EN 12453 for safety in use. For the ongoing care of the docks, see our guide to loading bay maintenance.
Questions
When should a loading bay specialist be involved in a new warehouse?
As early as possible, ideally while the slab, dock walls and yard are being designed. Leveller pits, embedded steel, ducts and openings are built into the structure, so the equipment needs to be selected before those details are fixed. Early involvement lets the design team work to real pit drawings and power requirements instead of generic allowances, which reduces changes later in the build.
Should every dock on a new warehouse have a vehicle restraint?
HSE guidance says there must be safeguards against drivers driving away too early, and restraints are one of the measures, alongside traffic lights and keeping keys or paperwork until it is safe. Fitting restraints on every dock gives a consistent system, but the right approach depends on your risk assessment, vehicles and procedures. Providing ducts and power for restraints at build stage is easier than adding them later.
Who forms the leveller pits, the civils contractor or the dock installer?
Usually the civils or main contractor forms the pits, casts in the embedded steel and lays the ducts, working to drawings and details from the dock equipment supplier. The dock installer then checks the pits and steel before installing the levellers. The split should be written into the contract and the drawings, so there is no gap in responsibility between the two packages.
What documents should we receive at handover?
Expect commissioning records for each bay, operation and maintenance manuals, drawings, declarations of conformity and marking information for powered doors and dock equipment, the manufacturer's warranty details and written workmanship terms. You should also receive training for staff and a planned maintenance and inspection schedule, so the equipment can be maintained and inspected under PUWER and, where it applies, LOLER.