The speed of trolleys and cranes depends upon the length of the runway or the size of the area covered. Generally, faster speeds are used for longer runways. Short runways will run at slower speeds. If floor areas are crowded or congested, then slower speeds will probably be desirable. The slower the speed, the more accurately loads can be positioned. Maximum flexibility is gained with variable speed cranes. The fast speeds are used for long runs and the slower speeds for positioning. Single speed hoists are the most popular in light capacity and meet most requirements at substantial savings. Two speed hoists are most common at five ton and heavier. The following is a guide to speed selection. If in doubt, order the slower speed. Operators seldom complain about speeds being too slow. Speeds which are too fast can create problems.
Hoist Lifting Speeds:
Lifting speeds are largely determined by the application and use. Average speed is generally between 10 and 20 fpm. Speeds under 10 fpm are usually not practical except in special cases. For some continuous uses, speeds faster than 20 fpm may be desirable.
Most hoist motors are rated for 15 minute continuous operation. By dividing length of lift by lifting speed in feet per minute, you can determine if you have exceeded this rating. If there is any doubt, contact CraneTec.
On two speed hoists, the slow speed is generally one-fourth the hoist main speed. Hoist creep speeds are generally one-tenth the main hoist speed and variable speed hoists generally start at one-tenth and are variable to full speed.
Trolley Speeds:
The convenience of the operator and smoothness of travel are the principal factors in selection of the motorized trolley speed. For spans up to 60’, 65 FPM, is generally recommended. For longer spans, 80 fpm may be more efficient. The average walking speed is about 100 fpm.
Bridge Travel Speeds:
The length of the runway, type of load carried, and operator safety and convenience are the important factors in speed selection. For floor operated cranes and runways up to 100′, one hundred fpm will usually be recommended. For runs over 200′, one hundred and thirty fpm may be more satisfactory.
Radio controlled speed cranes can range from 160 fpm to 350 fpm. The specific operating conditions will determine which speed is best. Bridge speeds are variable speeds from 10% of the chosen speed to 100 percent.