||This article possibly contains original research. (May 2010) (Learn how and when to remove this template message)|
A yard ramp, sometimes called mobile yard ramp or container ramp, is a movable metal ramp for loading and unloading of shipping containers and vehicle trailers, without the need for permanent docking bays. A yard ramp is placed at the back of a vehicle to provide access for forklifts to ascend the ramp, quickly and safely into the container or truck body.
Using a yard ramp for container loading or unloading allows the work to be carried out by a single forklift operator. Businesses handling only one or two loads per day normally find that a yard ramp is more cost effective than a permanent loading dock.
Advantages of a yard ramp
Containers, trucks and trailers are typically loaded / unloaded from the rear by reversing the vehicle up against a raised concrete loading bay, the cargo is then moved using counterbalanced forklift trucks. The loading bay is designed to be at approximately the height of the vehicle with a leveling device to accommodate any height differences. There are however many situations where it is not possible to utilize a permanent loading bay. In these situations, a yard ramp is an ideal solution, providing fast, efficient loading and unloading of trucks/trailers by forklifts. The possession of a yard ramp also provides a backup in case of any problems encountered with a normal loading bay/dock leveler system, and can also provide additional flexibility should vehicles be encountered that the normal loading bay cannot cope with.
Yard ramps can also be used either inside or outside of buildings; they avoid the need to construct expensive permanent concrete docking bays; and are ideal for short term use in peak periods or on temporary sites.
Additionally, yard ramps normally incorporate a tow bar or ramp clamp allowing them to be quickly and easily moved around on site by forklift and placed in a new location as required. Their mobile design makes them ideal for small sites where space is a premium, or sites with rapidly changing operations/requirements.
Yard ramp design
Some yard ramps are constructed from aluminum, but although this has weight advantages, their cost is typically much higher than their steel equivalents; most yard ramps are therefore constructed from welded steel unless the weather conditions are such that aluminum needs to be used, i.e. in climates with temperatures well below freezing.
There are a variety of choices for the decking material as it is required to be both tough and non-slip in a range of operating conditions. Most manufacturers use some form of open grill sheeting supported on a rugged base structure.
The basic layout of a yard ramp is an inclined section of about 9 m (29'6") in length and 2.25 m (7'5") in width, followed by a flat approach section of about 2.5 m (8'3") in length at the top, with a lip to enter the container or truck being loaded or unloaded. Both sides of the ramp usually have safety rails to prevent forklifts from accidentally driving over the edges. The yard ramp is supported on an undercarriage, or adjustable legs, fitted with wheels which are used to transport the yard ramps around.
The undercarriage/legs are adjustable so that the height of the ramp can be raised whilst the truck is put into position, and then the yard ramp is lowered so that the front lip supports the weight of the yard ramp on the container or truck floor. It is then vitally important that the yard ramp is allowed to float up and down with the vehicle as it raises/lowers on its suspension.
Standard yard ramp features
Although most mobile yard ramps are generally of a similar design, it is important to be aware of their individual features, and the potential impact they can have on operations:
- Usable width – It is strongly recommended to use a "full width" yard ramp which is the width of a container for the full length of the ramp. Some ramps on the market are narrow for the majority of their length, but flare out at the top. This can require additional positioning and can prevent pallets entering the vehicle parallel. Some yard ramps are supplied narrower to allow them to be shipped in a container, ideally however they should be full width.
- Capacity – The industry standard capacity ramp is rated at 10 tonnes (22,000 lb), but some manufacturers produce alternative light duty 7-tonne (15,000 lb) models, and some produce heavy duty 12-tonne (26,000 lb), 15-tonne (33,000 lb) or higher capacity yard ramps dependent upon the customers’ requirements.
- A level-off section at the top of the yard ramp is required so that the load is inserted as parallel as possible to the floor of the vehicle, preventing impact with the roof, and also improving visibility for positioning.
- The working height of mobile yard ramps needs to be adjustable to suit varying vehicle bed heights. The working height will also alter slightly as the vehicle is loaded or unloaded and moves on its suspension. Normally a working range of 1.0 to 1.7 m (3'3" to 5'7") is considered suitable as that allows the ramp to reach containers at around 1525 mm (5'0"), down to Euro Trailers at around 915 mm (3'0").
- A full width exit lip which sits securely on the bed of the vehicle to allow full width access to the vehicle/container. If the lip is narrower there is a risk of fork trucks falling or getting stuck in gaps between the ramp and vehicle. A few ramps have strengthening ribs on the top of the exit lip which can narrow the usable width and interfere with the loading/unloading operation, preventing the final pallets being loaded with the ramp.
- Fully mobile design with an easily operated tow mechanism; allowing the yard ramp to be quickly and easily manoeuvred into position on the vehicle, or stored away until next needed.
Essential safety features:
- A means of preventing the yard ramp and vehicle from creeping apart during use.
- Safety rails to prevent fork trucks driving off the sides during use.
- High traction, non-slip flooring along the length of the yard ramp.
- Adequate signage to cover functions/instructions for the ramp.
- The ramp should 'float’ up and down with the vehicle as it moves on its suspension during the loading/unloading operation.
- Handrails along the full length, if the yard ramp is likely to be used by personnel.
- Safe working load must be clearly stated.
Selecting the right yardramp
Careful consideration must be taken when selecting the correct yardramp for each application. The manufacturer should be able to provide information to help select the correct model, but important things to consider are:
- Capacity or rated load – The rated capacity of the ramp must always exceed the greatest total moving load (including goods, persons and transport equipment). If there is any likelihood of changes to operations; it is always better to over specify than under specify. It is also vitally important to be aware if quoted capacities are total load (uniformly distributed load: UDL), or single axle (dynamic load) capacities. Under heavy braking it is quite feasible to have the full weight of the fork truck acting through its front wheels only, therefore it is important to ensure the single axle rating of the ramp is sufficiently high.
- Frequency of use – High frequency usage, e.g. shift working can cause damage to light duty ramps which are only designed for occasional use.
- The load to be moved – The ramp must not restrict the movement of the load sizes required. Narrow, high side curbs are a hindrance if trying to load wide items, and long, tall items may foul on the top of the container if the level off top section at the top is too short.
- Usable width – This is typically full vehicle width, i.e. around 2.25 m (7'5") to allow straight access into the vehicle without the need for repositioning at the top of the ramp.
- The type of fork truck – 3-wheeled fork trucks for example will put additional pressure on the flooring of the yard ramp. It is also important to check the trucks to be used are capable of running safely on the incline at which the yard ramp will be working at, and have no under clearance problems.
- Height range – The maximum recommended incline of a yard ramp is 7 degrees or 1 in 8, though some yard ramps are capable of raising beyond this angle.
- Movement of the yard ramp – Yard ramps are typically moved around using a simple tow bar which is pinned into the tow hitch on the back of most standard fork trucks, though some designs offer alternative methods, such as pushing the ramp around using pockets which accept the standard forks of a fork truck.
- Yard surface - If the ramp is to be regularly towed across rough or stony surfaces, or towed at high speeds then it is preferable to have a ramp fitted with conventional pneumatic tires rather than the cheaper solid tires normally used as standard on many European ramps.
As with any equipment, there are standards, directives and regulations that should all be fully considered to ensure that a yard ramp meets the legislative requirements for the country in which it is being used.
In Europe CE Marking is a manufacturer’s declaration that a product complies with the provisions of all applicable Directives, including the essential safety and health requirements, and is proven by the demonstration of a route of compliance.