Dock shelters and seals play a big role in maintaining efficiency and saving energy in warehouses with internal loading/unloading bays. But with various options to choose from which is right for a given application? Guy Windle of sara LBS examines the relative merits of standard, retractable and inflatable dock shelters.
The unpredictability of British weather means that, every day, opening a door is a journey into the unknown. For a busy warehouse, the challenges of maintaining a given ambient temperature can be severe, with heat loss – or indeed heat ingress– being a significant issue. From a thermal efficiency perspective, every time the loading bay doors are opened, it is potentially costing you money in terms of heating or cooling the warehouse environment. Wind, snow and rain encroaching into the workplace can also compromise production or damage goods; as well as having implications for safety and hygiene.
It is no surprise, then, that dock shelters have become a popular option as the interface between the warehouse and the lorry. Rugged and robust, they form an effective seal against the lorry during loading and unloading, and reduce heat/chill loss from thermally regulated premises or vehicles. They also protect goods and operatives from the extremes of the weather.
Heavy duty by design and extremely cost effective when considered against the energy savings they enable in maintaining the warehouse ambient temperature, dock shelters offer a low maintenance solution to sealing the gap between the loading bay and the vehicle body. Curtains protect goods from the weather and help to maintain warehouse temperature. Easy to install, they can be readily integrated with traffic light controls, internal dock lights and other automated warehouse systems.
When looking at a dock shelter for a given application, there are three primary options: rigid, retractable and inflatable. The standard, rigid dock shelter is designed to allow unobstructed access to the rear of the vehicle for easy loading or unloading. They provide good all-round protection from the outside elements, employing two vertical side curtains and a horizontal head curtain to provide an effective seal against the vehicle.
The same benefits are also provided by retractable dock shelters, but these offer the additional advantage of folding back if struck by a poorly parked vehicle. This not only reduces the possibility of impact damage, but also ensures an effective seal is established. Once the vehicle leaves the bay the shelter will return to its original position.
sara LBS rigid and retractable dock shelters are manufactured with a choice of three frame constructions: galvanised steel box sections with Plastisol colour coated sheeting, and raked roof; treated timber clad in black PVC/polyester heavy duty fabric, with sloping roof rear-to-front; or insulated side and roof panels finished with steel colour-coated white Plastisol sheets, sloping roof rear-to-front.
Dock level models have steel supporting brackets under each side panel fixed to dock face. Curtains are constructed and machine stitched in heavy duty 3mm thick PVC Derco, and all fabrics are specially coated and are colourfast. The standard dock level model is available up to 3,500mm wide x 3,500mm high, 600mm projection with head curtain drop 1,200mm and side curtains of 650mm width each. Special sizes can be constructed to suit other applications.
The third option for dock shelters is the inflatable model. Here, once the vehicle is docked at the shelter, the side and head curtains are inflated to provide a weather-tight, energy-efficient seal against the vehicle.
Inflatable dock seals provide an excellent solution for warehouses working with a wide range of vehicle heights. Hygiene regulations are catered for, and the internal retraction system for the side air bags gives a smart and tidy appearance. The enclosed, counter-balanced weight retraction system for the head seal ensures that that it is discretely stored away when deflated.
A typical system takes around ten seconds to inflate and seal against the vehicle, and importantly it offers an effective seal without putting any major loading on the building. This means the inflatable dock shelter is suitable for use on buildings with a light duty construction.
Having spotted early on an increased demand from industry for this high-quality type of seal, sara LBS is at the forefront of inflatable dock shelter design, with three distinct models. The first includes fully insulated side panels to meet current hygiene regulations with head frame finished in white Plastisol steel and sloping rear-to-front roof for drainage. Side storage curtains in black 3.5mm thick PVC for air bag protection secured by aluminium angle around three sides. Both side storage curtains have stitched yellow traffic-guide arrows for safe vehicle positioning.
The second inflatable model is narrower in overall width to allow for more units on interface but without fixed side panels to assist vehicle movement. Air bags inflate directly from wall position behind the buffer line and are specifically designed to seal the gap between vehicle door hinges.
The third inflatable model is designed to allow side air bags to inflate direct from the building to totally enclose the vehicle rear and seal on vehicle sides. The insulated roof and the design of the deflated air bags bring an important benefit in that the vehicles can have the maximum manoeuvring space on entry and exit.
Air bag construction is machine-stitched heavy-duty 610gm/m2 black PVC/polyester material. All curtain materials are colourfast and designed for external use. The side air bag seals have an internal retraction system to allow them to lie flat behind the storage curtain when not in use. The head air bag seal, which is full width across and in front of the side seals, is retracted automatically by a weight operated roller system in the head.
For any business with regular warehouse loading and unloading, the dock shelter is an important consideration. For the warehouse to be thermally efficient, hygienically safe and operationally productive, businesses need to get the choice of dock shelter right.