Fire apparatus weight distribution and access rd design

[iceng]

Would you please tell me what is meant by Fire apparatus weighing at least 80,000 lbs, how much of an axial load does have and how much of it per LF to design the access rd on gravel.

Thanks

 

[MiketheEngineer]

This is probably an AASHTO requirement - check that forum.

Also the AASHTO guide will show you how to distribute that load. I don't have it on me -- otherwise I would share that info with you --- but it is your job.

 

[kslee1000]

This is a heavy fire equipment. It would probably loaded on a flat bed trailer. You need to know the type of truck, number of axiles, and its weight. You also need geotech's help to determine the property of the gravel road. If there is a bridge enroute, you will need to know its capacity as well. Plan ahead, there are lots of works involved, and dealings with local officials (for permit).

 

[msquared48]

The critical load will not be the axle load here, but the outrigger load. You need to get that spec from the local fire marshall.

Mike McCann
MMC Engineering

 

[iceng]

Thank you all, I have talked with the fire department inspector, and basically they have not thought about this issue in a meaningful way.
They have no idea if this is load double axle load, and what is load distribution on the front and back what is the width of the tires......

After all the regular roads and street carry these trucks with 6" ABC stones substrata layer with 2" asphalt.

T think this should be the maximum thickness, since this is an emergency turn around hammerhead.

What do you thinks guys.

 

[msquared48]

Again, if this is a large ladder truck, don't forget the outrigger load in punching shear.

Mike McCann
MMC Engineering