Views: 262 Author: Fullwon Publish Time: 2019-04-23 Origin: Site
Lumber? Drywall? Heating, ventilation and air conditioning (HVAC) units? The payload has as much impact on the truck supporting the crane as it does on the crane itself. Knowing the weight and size of the average payload will dictate elements such as size, type, bed and body length, wheel base and frame strength of the truck that should be selected for the crane.
Every truck has a resisting bending moment (RBM), the point at which a truck frame might fail under too much force. The truck’s RBM, which can be obtained from the truck’s manufacturer or dealer, will dictate whether it is necessary to add a support structure to the truck frame. Factoring a truck’s RBM will prevent adding too much crane to the vehicle on which it will be transported. A 50-metric ton crane, for example, would immobilize a Ford F-150 chassis.
Every city and state has its own regulations for the legal height, weight, length and width of vehicles. The crane-truck combination is no exception. It would be unfortunate to nicely fit the truck and crane together, only to learn the truck and crane exceed the legal height or weight restrictions for traveling on public roads. Make sure to consult the proper authorities for acceptable length, width, height, weight and emissions configurations. Most crane manufacturers can supply an estimated dimension and weight distribution report to better inform a buyer.
The work application of the truck and crane combination is probably the most important factor in determining which end of the truck frame the crane is mounted. Mounting the crane on the truck’s rear, the most common unloading point, greatly extends its useful reach compared to a crane mounted behind the cab. This, however, puts more load on the rear axle, which might affect the truck payload capacity. In applications where most loading is from the side rather than the rear, the crane will usually be mounted behind the cab.
The position of a crane also affects how a truck performs while the entire unit is on the road. An improperly positioned crane, even one that is an appropriate weight for a truck, can cause the truck to be unsafe for over-the-road use. A crane positioned on the rear of a truck bed will have an effect on front wheel traction and vice versa, which should be a consideration as to whether additional axles are needed.
Determining how the operator will control a crane is as important as the kind of loads that will be lifted. A key element is visibility, which might take on complications based on where a crane is mounted. A fixed control station might result in obscured visibility when a crane is placed on a truck. A top seat station offers better visibility, but might be too far removed from the lifting area for some operators. Remote controlled operation allows an operator to have greater visibility and offers an increased safety advantage by allowing the operator to stay a safer distance from the load. Some operators might choose to employ a hybrid of these types, but, whatever decision is made, it is better to decide what control works best with individual operating needs and how that visibility might be affected by a crane’s location on a truck frame.
Is the truck and crane configuration conducive to easy, regular maintenance and service? If the design of a crane and truck unit presents obstructions to important components such as the oil plug, air and oil filters, belts and hoses, simple maintenance becomes expensive and time consuming. As a result, costs for regular maintenance might reduce the advantages of owning the equipment. Even worse, the operator might delay or ignore regular service schedules and find the equipment in need of more complex repairs. A properly designed equipment configuration makes regular service uncomplicated, keeping the equipment on the job.
Also consider the placement of ergonomic or convenience features. Determine whether the addition of ladders or grab rails to the truck body or crane could help an operator or service person maneuver more easily around the equipment.
A capable support team is as important after equipment rolls onto the worksite as it is when planning that equipment’s configuration. Can the crane provider anticipate the operator’s needs and service the equipment on a routine basis? How experienced are the provider’s service technicians, and what is the approximate wait time for a scheduled service? Can any competent, certified repair technician complete the service or repair, or will the operator pay to transport the equipment to a service center—an extra step that might add thousands of dollars in transit costs in addition to the cost of actual servicing?
It pays to invest whatever extra time is necessary in the planning and design stages to consider factors that are likely to affect the equipment’s performance. Enlist the help of the people most likely to use the equipment as well as the engineers and technicians who will assemble the components. Problem solving on paper will be far less complicated and costly than troubleshooting on a jobsite.