It would be hard to say that landing legs are glamorous; that drivers boast about their favourite landing gears; or that battles have been won and lost over them. However, they are a vitally important for the safe execution of many haulage applications and it is fair to say that the logistics world would grind to a halt without them.
Landing legs - also called telescopic landing gears - are the retractable undercarriage located towards the front of the underside of trailers. They are normally retracted into a storage position when not in use, but are lowered to take the weight of the trailer when the tractor is uncoupled and driven away. As such they are often critically important for the efficient and successful delivery of goods.
In fact there are many different designs of landing legs, and appropriate ones must be fitted to each trailer. JOST has developed its Modul series of landing legs using a modular format that allows mixing and matching of various components to achieve an optimum design for each application.
Probably the most obvious requirement is strength. No trailer is light, but some are heavier than others and it is necessary that the chosen landing legs are strong enough to support the maximum likely load plus a generous safety margin. However it should be noted that heavy duty legs weigh more, are more bulky and more expensive than standard ones, so there is a balance to be achieved.
Most landing legs are made of steel, but aluminium offers a considerable weight advantage and is often considered particularly suited to tank and silo vehicles.
Truck drivers will tell you that life on the road can be hard going. But at least they are protected by a comfortable cab! Landing legs, by contrast, have a really tough working environment. Located under a trailer, they are subject not only to the weather, but also salt spray and frequent impacts from stones and general roadside debris.
For this reason landing legs have to be exceptionally sturdy in order to resist such unfavourable environmental conditions. They need careful pre-treatment, including thorough powder coating, and to be designed with minimal cracks and crevices where water and dirt could collect.
Their designers also need to consider the realities of on-going maintenance. It is a simple truth that regular and thorough maintenance of the landing gear may not be uppermost in operators’ minds. For this reason JOST keeps its designs simple but effective and uses a long lasting lubricant. It also supports a worldwide service and distribution network which, as well as spares, can provide technical support.
In fact, JOST provides a three year guarantee for its landing legs, so that operators have long term peace of mind. This is achieved through operating rigorous manufacturing process controls including, ISO quality and environmental standards.
The drive mechanism by which the Modul legs are deployed or retracted is patented and is designed so that it is protected by a strong yet compact housing. In addition, it has high and low gear settings for ease of use, with the change between the two settings being straightforward. The drive is also secured against unexpected run-down.
Each leg is fitted with a foot, and there are several designs to choose from, including a flat foot, a rocking foot, a ‘sand shoe’ and a wheel. These are easy to mount securely onto the legs and are free to pivot so that full contact is made with the ground.
Options are available where the drive can be cranked from either side, a very convenient feature in crowded locations, such as on ferries or in busy lorry parks. As well as standard landing gears, JOST also offers: drawbar landing gears with pivot bearings for use in combination with central axle trailers and dollies; especially robust telescopic landing gears for heavy duty applications, and a rear stabiliser which can be used in tipping application.