Old Versus New: 15 Years of Gray & Adams Double Deck Innovation The Henderson Group

The Henderson Group, based in Newtownabbey, Co. Antrim, was one of the pioneers of the double deck trailer in the food distribution industry. The company was one of the first to venture into the operation of double deck trailers and had their first double deck manufactured by Gray & Adams Ltd. in 1994. At this time, Gray & Adams was only manufacturing this type of trailer in very small volumes and was still developing the product technically. Over the years, Gray & Adams has refined the double deck manufacturing process, making a number of significant changes and additions which have resulted in double decks now accounting for a large proportion of Gray & Adams entire trailer production.

In 2009, the Henderson Group took delivery of new dry freight double deck trailers from Gray & Adams. Although these trailers are a variation on the original specification from 1994, the trailers have undergone many significant design changes.

Probably the most significant of these changes is the substantial reduction in the unladen weight, meaning that a much greater payload can now be achieved. Through the use of different types of materials in the trailer construction, the weight has been reduced without compromising strength or durability. Other design changes have been aimed at reducing maintenance costs and making maintenance easier, in order to ultimately reduce downtime, such as the combination of technologically advanced Tridec suspension with modern BPW running gear.

The new Henderson double decks have a unique air suspension system, rather than a manual jack to facilitate efficient wheel changing. All valves, brake cylinders and electrical equipment are now easily accessed through inspection hatches, again to help minimise downtime. A roll stability system is also included which has particular benefits for a double deck trailer due to the high centre of gravity of the trailer.

Although the original Henderson double decks and the new ones are similar in the rear roller shutter door set-up, the new trailer system has been advanced massively from the manually operated type used in the 1994 construction. The new system is electronically operated, which offers a number of benefits. Firstly, Health and Safety is improved as the risk of back injury is eliminated with the removal of the manual element and unlike pneumatically operated doors, the electronic system has a built in mechanism which stops the door from closing should any object be obstructing the rear threshold, whether it be a loadlok bar, pallet or even the operator. Also, because the door opens and closes at the same speed every time, there is reduced wear and tear on the balance springs and wire ropes and because the door cannot move backwards and forwards if the trailer is driven with the door in the open position, there is less potential for damage to the door mechanism. In the unlikely event of a power failure, the electronic operation can be overridden to use the door manually so that distribution is not halted by a breakdown.

In the 1990s there was a very limited choice of two-tier tail lifts available on the market and only one manufacturer who was able to provide a specification suitable for Henderson's operation. Even at this, Gray & Adams had to modify the platform and make up ramp plates etc. This obviously affected the scope for advanced functionality at the time. The new trailers are fitted with a Dhollandia tail lift which has a number of features fitted that were not previously available. For example, dual-purpose factory fitted side ramps also act as gates to add security for operators when the lift is in use and are manufactured using alloy to keep weight to a minimum. One other important feature of the tail lift is the external button controls that allow operators to raise and lower the lift without the use of a wander lead.

"Trying to prevent the cables and button controls from being damaged has always been a problem within our distribution fleet and in fact throughout the rest of the industry, especially on double deck trailers. Being able to do away with wanderlead operation will be a massive benefit to our company, particularly in terms of cost". - Ian Gibson, Transport Manager, the Henderson Group

With regard to the environmental aspect of the twin deck trailer, a fixed deck design can offer up to 70% increased capacity (slightly less on a wheelbox configuration like the Henderson trailers) compared to a standard trailer meaning that less vehicle movements are required and therefore overall operating costs are lowered. As well as this fundamental benefit, the Henderson trailers have additional features aimed at reducing cost and environmental damage. Firstly, the trailer has a tapered roof which makes airflow over the top of the trailer smoother and therefore increases the aerodynamic capability, which helps to further reduce fuel consumption and subsequently CO₂ emissions. A unique solar panel feature is incorporated on the roof to provide additional trickle charge to auxiliary batteries. As well as the environmental benefits resulting from the use of a natural power source, it means that the tractor unit does not always need to be connected to use the tail lift when loading and unloading.

Whilst the Henderson double deck specification is a dry freight, fixed deck wheel box type with 22.5 inch rims, Gray & Adams has developed the twin deck range to incorporate a wide range of options, including single and multi-temperature, insulated and dry freight, and fixed and lifting deck combinations. There are currently over 1000 Gray & Adams twin decks in operation across the UK and Ireland, being used in operations ranging from parcel delivery to ambient, chilled and frozen food and dry goods distribution.

"We constantly try to update and improve equipment throughout all aspects of our business to keep a competitive edge. In my opinion the Gray & Adams double deck is the most up-to-date and innovative product currently on the market and when we researched new suppliers, Gray & Adams could offer the product that was best suited to our operation. We are very impressed by our experience with Gray & Adams and our drivers have commented on how operator-friendly the trailers are...Gray & Adams offers the entire package from the most appropriate product right through to the back-up service provided. The fixed cost maintenance package and guaranteed breakdown response times give us great peace-of-mind and will minimise the disruption to our operation should a breakdown occur. There are also massive benefits of the Gray & Adams one-stop-shop in terms of planning and budgeting for trailer costs and one source paperwork and contact details". - Ian Gibson, Transport Manager, the Henderson Group

When the first Gray & Adams double deck trailers were first introduced to Hendersons, all maintenance was carried out on a pay-as-you-go basis. This obviously made controlling and budgeting maintenance costs difficult. In 2004, Gray & Adams (Ireland) Ltd. introduced a purpose-built five-bay repairs facility, which can now cater for all trailer and body maintenance and repairs. In particular, running gear and tail lift servicing can all be done under one roof and all routine maintenance can be set-up on a fixed price contract for up to seven years. Hendersons have taken advantage of this facility for the maximum number of years available.

The Henderson Group introduced symbol group trading to Northern Ireland and is now the largest operator of its kind in the province, supplying over 400 stores, encompassing Spar, Vivo, EuroSpar and VivoXtra. Henderson's logistics incorporates seven day deliveries, with most stores receiving six fresh, two/three ambient and one/two frozen deliveries every week.