Thread: new truck body construction
08-14-2004, 01:33 AM #1
new truck body construction
We have spec'd what we think we want for a new pumper. We have received several bids all for aluminum (what we want) difference is gauge/thickness, some have spec'd 1/8"(Central,Pierce) some have 3/16"(E-one and others).
I know, of course, 3/16" is bigger than 1/8", but is there a large structural difference, will they both last 20yrs?
08-15-2004, 03:49 AM #2
Alexis' claim to fame is using 3/16" aluminum, which makes it "heavy duty." Is bigger always better? We don't have a 20 year old Alexis, but our 1991 engine's bodies are holding up fine. The old Ford C/E-One rescue we had held up great too - the unit just didn't fit department needs anymore. We had that one over 20 years... I would assume that E-One was building with 3/16" then as well.
We've rejected bids for anything less that 3/16" aluminum in the past, so obviously my department is partial to the thicker material. However, I would suspect that a competent manufacturer (i.e. Pierce) compensates for the lesser strength of a thinner panel by beefing up the framing supporting it. Someone else here must know a definitive answer. Using thinner sheet must be a cost savings though for a manufacturer, no doubt about it.
08-15-2004, 10:42 PM #3
I know that Sutphen uses 3/16" thickness on even it's lowest end units. It has been shown that it takes thicker aluminum to match the strength of a thinner steel. I'm with BJL, Pierce may just beef up thier supports to compensate. I have spoke with a couple of department personnel from the area who are not real happy with the newer Pierce bodies though. They have told me that the thinner bodies are cracking out. This is only what I have been told and not personnal experience. I do know that 3/16" is not substancially heavier weight wise than 1/8", so I say go with the thicker stuff.
08-16-2004, 09:04 AM #4
Will they both last 20 yrs.Yes. Is 3/16s better than 1/8?No question!We rejected a bid on 1/8 and had the Mfg redo it in 3/16. Would you rather stand on a ladder made of beer can or one made of electrical conduit? T.C.
08-16-2004, 07:10 PM #5
- Join Date
- Apr 2004
Aluminum will "fatigue" quicker than steel or stainless steel, so where 1/8 stainless will do, you might need 3/16 aluminum. That's for the long haul. The aluminum bodies on our E-ones are still rock solid after 10 & 11 years.
08-24-2004, 06:53 PM #6
- Join Date
- Aug 2004
Fire Apparatus Bodies
Extruded Aluminum is the way to go! The formed bodies of yesterday and today will be a thing of the past in the not so distant future. I do believe that extruded aluminum will become the "standard". As for the thickness of the aluminum, 3/16 is better than 1/8. That being said, I'd take a 1/8 EXTRUDED aluminum body over a formed metal or formed aluminum body any day!
As far as I know... E-One's standard is 1/8 but will do 3/16 for alot higher price. General and Central States build 3/16. Pierce will not build an EXTRUDED aluminum body - only a formed aluminum. Ferrara will build almost any type of body but, with my FDs experience with them, I'd buy a Yugo and throw a portable pump in the back seat and take my chances before I bought from or even CONSIDERED them.
Bottom line... spec an EXTRUDED ALUMINUM BODY and reject anything else (formed metal or formed aluminum). As far as the thickness... spec what you are willing to pay for.
08-25-2004, 02:58 AM #7
- Join Date
- Apr 2004
E-One uses 3/16" plate extruded aluminum on their bodies, not 1/8". I'm sure they will build a unit with 1/8" but their standard is 3/16". We have a 1995 engine with an extruded aluminum body and it has held up very well.
Last edited by BVFDCaptain503; 08-25-2004 at 03:01 AM.
08-26-2004, 05:04 PM #8
- Join Date
- Apr 2003
Another area to look at are the material properties for the body materials. Review the tensile strength, yield strength, Brinell hardness and endurance limit. I think any manufacture can provide those and/or be found in a machinery habd book or metals reference book. I looked this up in a older set of truck specifications we sent out for a pumper we have.
If I remember correctly, You can have thinner materials that are stronger then thicker ones. I guess one way to thick of it as look a carbon fiber. It's very light in weight and thin, but very strong as say compared say steel in general. Our department ended up going with Pierce with the last unit, but we also have a S/S Seagrave and two older E-ones. Hope this helps.
08-27-2004, 12:34 PM #9
Hey firefish - way to go! Nothin' better than an informed opinion that's backed by facts. We buy apparatus every year - and hear the same song every year from each of the "big" manufacturers. They WILL try to sell you what's easiest for them, not always what's best. The best advice I could ever offer is to be patient and do your research as you have obviously done. (and the salesman is just that - he won't be the one repairing the truck 10 years down the road)
08-27-2004, 03:40 PM #10
- Join Date
- Nov 2003
I am not aware of any other company that does this, but Custom Fire Apparatus bolts their bodies together, rather than weld them. It allows for the bodies to be shipped in crates (I believe they sent some to Saudi Arabia), no possibility of broken or cracked welds, and allows for easy repair.-Bozz
Air Force Medic
09-14-2004, 11:36 AM #11
Firefish - the terms you are looking for in reference to the ability to form metal are ductility and malleability. Brinnel is a hardness range, as is Rockwell. There are many other "tests" such as charpy and izod that determine how well a material forms.
But you are on the right track with the strenght vs thickness vs cost analysis.
Also, if you purchase a truck with large extruded panels, what happens when someone t-bones your rig? With companies that CNC cut/form their panel (and file the programs for your body) you can get exact replacement parts down the road.
Extrusions are one means of metal forming. An extruded body is formed by an extrusion process. The appararatus bodies, regardless of exact method are large rectangular boxes. The "extrusion is best" is kind of/sort of a salesman statement, one that in theory may be correct, but in application may not make a difference.
I'll use a chainsaw analogy. We were discussing a new chainsaw .
The Husquavarna propenent piped up with "I buy Husquavarna saws for my day job with the state highway dept because they have bar oil pump drives. The Stihl drive is a cable and more likely to break. I immediately asked him if the Husquavarna salesman told him that. Yup. I don't care what kind of drive shaft my Stihl has. It's never given me any problems. And the Stihl, being designed for loggers by loggers has a two ring piston design that IMO is better than the single ring Husky. Be carefull of what salesmen tell you.
Aluminum bodies are still attached to a carbon steel chassis. Some have subframes of varying materials. One issue to look out for with aluminum is electrolisis due to dissimilar materials.
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