Chassis Question ?

[NewJerseyFFII]

I am looking for information on custom chassis frame rails for " Aerial Trucks "! What is the standard type frame rail on the following apparatus, 75' stick single axle , 100' stick tandem ,& platform & Aerialscope. Single,Double, Triple channel rails. Also want apparatus builders make a chassis with triple frame rails that would accommodate a Scope Superstructure Assembly.On all other aerial ladders & towers a steel torque box carries most of the bearing load to reduce the flexing while driving highway speeds ?

[chiefengineer11]

I don't know much about HME's offerings but Spartan does have all three available. Above certain weights and for certain applications they will require double or triple rails, otherwise they're optional.

Stay safe out there, everyone goes home!

[Rescue101]

NJ,It's a loaded question with NO concise answer.Rails will be MFG specific to the device as will frt and rear axles.A Sutphen won't use the same rail spec as say a Ferrera.To answer one part of your question:ANY of the major players can build/acquire rails up to triples with RBM's approaching 5mil section.But this will be determined by the engineers of a specific device for a specific application.If I knew specifically who's device you were looking at we could probably get some hard numbers.But you can do this yourself once you've narrowed the field.T.C.

[NewJerseyFFII]

NJ,It's a loaded question with NO concise answer.Rails will be MFG specific to the device as will frt and rear axles.A Sutphen won't use the same rail spec as say a Ferrera.To answer one part of your question:ANY of the major players can build/acquire rails up to triples with RBM's approaching 5mil section.But this will be determined by the engineers of a specific device for a specific application.If I knew specifically who's device you were looking at we could probably get some hard numbers.But you can do this yourself once you've narrowed the field.T.C.

The device would be a refurbed 75' Scope,and or a 75' Midmount platform. I have heard that only Pierce ,Seagrave , and Spartan will build a triple frame rail chassis ?

[Chauffeur6]

On all other aerial ladders & towers a steel torque box carries most of the bearing load to reduce the flexing while driving highway speeds ?

Huh? I'm not sure I understand what you're asking, or you didn't phrase it right. While a torque box certainly provides structural rigidity and will help keep the entire chassis stiff while driving at highway speeds, that is NOT the primary purpose of a torque box. Not even close! Where did you hear that?

[Rescue101]

The purpose of the torque box is to handle the axial loads of the aerial device when it's working along with a spot to mount outriggers.You DON'T want to make the frame too stiff going down the road,if it doesn't flex it will break.There are a limited number of folks that seem to mount/remount 'scopes although IH makes a frame heavy enough to do so.On the 75' platform it will make a difference on the builder what the frame needs to be as I indicated earlier.An aluminum device would likely have a "lighter"frame than say a steel one.I didn't check HME but certainly the three you listed all build triple frames.On the commercial side,Mack and IH do as well. Now a 'scope on a Paystar would certainly be something to see,hehe T.C.

[chiefengineer11]

The purpose of the torque box is to handle the axial loads of the aerial device when it's working along with a spot to mount outriggers.You DON'T want to make the frame too stiff going down the road,if it doesn't flex it will break.There are a limited number of folks that seem to mount/remount 'scopes although IH makes a frame heavy enough to do so.On the 75' platform it will make a difference on the builder what the frame needs to be as I indicated earlier.An aluminum device would likely have a "lighter"frame than say a steel one.I didn't check HME but certainly the three you listed all build triple frames.On the commercial side,Mack and IH do as well. Now a 'scope on a Paystar would certainly be something to see,hehe T.C.

Likewise a DM or RD.

[NewJerseyFFII]

Huh? I'm not sure I understand what you're asking, or you didn't phrase it right. While a torque box certainly provides structural rigidity and will help keep the entire chassis stiff while driving at highway speeds, that is NOT the primary purpose of a torque box. Not even close! Where did you hear that?

Is the purpose of a steel torque box to mount a aerial ladder turntable to and also storage of ground ladders on a aerial apparatus, and a Aerialscope mounts right on the frame rails without a torque box and triple frame rails are needed to support the weight of the superstructure assembly & boom ?