This is only a guide to the main points that apply to Penny Hydraulics’ Trailer Cranes. Please refer directly to the original HSE documents for clarification.
We are the leader for installing cranes on trailers with applications across many sectors including rail, recovery, industrial pumps and logging.
It can be a great idea to fit a crane to a trailer as it leaves the towing vehicle free to carry its full payload, especially if a crane is not always required. There are, however, some key points that must be addressed for any trailer mounted crane to be a success. Penny Hydraulics never lets a trailer fitted with a crane leave its yard until it has been stability tested, weighed, hitch height checked, and nose weight taken to make sure that it is all safe and within the trailer and tow vehicle’s specified parameters.
Trailers are not designed to have cranes fitted to them and they offer little stability as they have little self-weight compared to a vehicle. Think carefully about what you need the crane to do and choose the smallest crane that will do the job. We then need to make sure that it will be safe both when in use and when being towed.
Once you know what you need to carry you can think about which trailer to buy. Always include the weight of the crane and mounting frame as well as your required payload in any calculation of carrying capacity. A crane system can weigh anywhere between 100kgs for a 250kgs SwingLift to 750kgs for a 2.0 tonne PH all hydraulic unit.
Pay particular attention to the maximum permissible nose weight for your trailer, (the “S“ value on the trailer data plate), and the maximum loading for your vehicle’s tow bar, (usually 80kg to 150kg). This often means that mounting a larger crane at the front of a trailer can easily exceed one or both of these values and result in it being unsafe to use on the road. Things to consider when choosing a trailer.
Check the data for your proposed towing vehicle. It is all published by the manufacturer and will be on a load plate on the vehicle.
Nose Weight.
Trailers are built to have a nose weight when empty to ensure stability. Adding a crane and support frame to the front of a trailer will generally take it above the permitted level for the hitch mechanism and towing vehicle. One way round this is to add equivalent counterbalance weights to the rear but this is expensive, takes up valuable payload and can make the trailer difficult to tow. Fitting the crane at the rear is more likely to be possible without adding extra weight to the trailer but all trailers are different and need to be assessed. The ideal position for a crane is mounted centrally.
Stability.
The trailer must not rely on the hitch or jockey wheel for stability when using the crane. Neither is designed for the sort of loads that may be imposed on them. Most crane and trailer combinations have two sliding support legs alongside the crane to go out on either side and also two more support legs that give stability at the opposite end of the trailer. This second pair of legs often just need to go to ground and may not need to slide out to the side. Some trailers with larger cranes will require ballast in the form of steel plates putting under the floor in the centre of the trailer to add stability. This will affect payload as well as cost.
How is the Crane to be Powered?
Large electric cranes require over 200 amps at peak load. Long cable runs from the front of a tow vehicle to the back of a long trailer will also use up significant energy. This can be offset to some extent by using heavy duty cables, but energy supply needs to be addressed. Are you going to fit a second deep cycle battery and if so, how will it be charged?
A better option for larger cranes is to fit a petrol-powered pump on the trailer although some electrical power will still be needed for safety circuits. This low power circuit is much easier to source from the tow vehicle but does mean that you cannot use the crane without the tow vehicle present. You may need to have a small battery on the trailer to make the whole unit self-sufficient.
Smaller cranes up to 1.0 tonne are more easily powered from the tow vehicle battery due to much lower energy requirements.
Operator Position.
In most cases there will need to be stops to limit the arc of the crane to a specified zone. This is not difficult, but you need to think about where you will be using the crane and where the operator will stand as they need to be in a safe place and not under the crane boom.
Penny Hydraulics will help you make sure that you have a successful crane/trailer/tow vehicle combination, but we need accurate data to work from.
The Load.
The Crane.
The data above will help us to specify a suitable crane. We then need to see if it can be safely fitted to the trailer/vehicle combination.
The Trailer.
The Tow Vehicle.
Line 5 is extremely important as it gives the maximum weight that the tow hitch can handle. In this case it is 100kgs. The figure should be preceded by an “0” but often is referred to as the “S” value. Both have been put on this plate. How the nose load is measured can give different readings, especially with multi-axle trailers. The trailer should be horizontal so that all axles share the load, and the tow hitch should be between 350mm and 420mm above the ground to be compliant with UK and EU regulations.
Lines 6 and 7 show that this trailer has two axles each with the same maximum permissible load of 1000 kgs. In order to reach the maximum all-up weight that this trailer can legally be at 2000kgs you would need to take care not to exceed each axle loading.
Details of the towing capacity for your vehicle that are found in the owner’s handbook, the manufacturer’s website and on other websites should only be taken as a guide. The actual, exact and only towing capacity figure that should be used for your vehicle is the one that is stamped on the Vehicle Identification Number Plate, VIN Plate.
The Tow Vehicle VIN Plate
The VIN plate will display either 3 or 4 sets of weights, it is these weights that VOSA or the other vehicle authorities use to determine whether your vehicle is towing or being driven within the law.
The manufacturer’s recommended maximum towing capacity for your vehicle is the gross vehicle weight subtracted from gross train weight. (4200kg – 2505kg = 1695Kg). This calculation is based on a fully laden vehicle. Note that some hybrid and battery vehicles cannot have towbars fitted and so no figure will be entered in position “B”.
We have used information from https://www.ntta.co.uk for this section.
Our range of cranes that are mounted to vehicles. Typically, these would be 3.5 tonne commercial vehicles such as vans and flatbed trucks.
Explore
