Bridge Cranes & AISE Technical Report No. 13
Bridge Cranes & AISE Technical Report No. 13
(OP)
I am working on a project to upgrade an existing crane rail system to a higher capacity.
The question I have is regarding the Longitudinal or Tractive force load. AISE states it is equal to 20 percent of the maximum load on driving wheels. Let's say for example my tractive force load is 0.2*45k wheel load=9k. Is that 9k load applied at each wheel or distributed amongst them.
This existing crane has two trucks with two wheels on each truck for a total of four wheels on each side. Right now I am using the tractive force load = 9k per wheel or 36k per side. Should it only be 9k/4 wheels=2.25k per wheel?
Thanks for the help...
The question I have is regarding the Longitudinal or Tractive force load. AISE states it is equal to 20 percent of the maximum load on driving wheels. Let's say for example my tractive force load is 0.2*45k wheel load=9k. Is that 9k load applied at each wheel or distributed amongst them.
This existing crane has two trucks with two wheels on each truck for a total of four wheels on each side. Right now I am using the tractive force load = 9k per wheel or 36k per side. Should it only be 9k/4 wheels=2.25k per wheel?
Thanks for the help...






RE: Bridge Cranes & AISE Technical Report No. 13
Note most crane has one driving axile, but some has two. Check with your crane supplier and asking for specific design considerations.
RE: Bridge Cranes & AISE Technical Report No. 13
For example, a 20 ton capacity crane with 2 wheel end trucks will impart the exact same acceleration & deceleration forces into the runway as a 4 wheel end truck (assuming the cranes weigh exactly the same)
Note that if a future crane is planned - one would add the forces of that crane into the total.
Note also, we use wheel load W/O impact.
I normally stay with the 10% unless there is a known variable that would increase it.
IE
The crane will be used in such a fashion that the operator will end up hitting the end stops repeatedly,
OR
In the case of an outdoor crane, wind load might increase longitudinal load (perhaps dramaticaly if a big crane.
OR
If its a very fast accelerating / Decelerating crane in a production environment, this could increase the forces. This is a rare occasion though, load swing on a standard hoist would be very problematic.
Most all cranes these days use VFD controlled motors which provides programable acceration & delceration rates. Hence, hitting the end stops might be the most important factor under "normal" circumstances. Or a power failure wich causes the brakes to Lock up and crane comes skidding to a stop.
BTW - does anyone know how to spell check these posts ?
RE: Bridge Cranes & AISE Technical Report No. 13
RE: Bridge Cranes & AISE Technical Report No. 13
RE: Bridge Cranes & AISE Technical Report No. 13
Then, I use the max wheel load w/o impact to determine the tractive force.
I also take into account that the tractive force not ony adds a longitudinal force in the girder but also a moment as the tractive force is applied at the rail height.