Gear ratio question

[atgreene]

My hometown fire department just was awarded another federal grant (that's 5 years in a row, btw!) for the remaining amount needed to purchase a 4000 gallon pumper/tanker.

We're replacing a 1987 General 13 speed with a 475 hp Detroit and a 3700 gallon tank. Originally a road tractor, I bought it when I was fire chief and mounted a tank we already had onto it.

Here's my question, we have a lot of hills. The new truck will be 500 hp with an automatic tranny. I'm looking to spec it with gearing that will top it out at 65 mph or so, as we really don't have any fast roads. Everywhere this truck goes is uphill, so we'd rather be able to climb rather than drive fast.

What should we spec into it?

Also, the chassis will be whatever manufacturer has the best deal, I suspect Int or Volvo, but we'll see. It will have full locking diff, jake, auto chains, heated mirrors etc... etc....

 

[Orchard Ex]

When I spec'ed my truck I used Cummins Power spec
http://www.powerspec.cummins.com/site/home/
to play with tranny, rear end, etc. to get cruise/top speed and startability numbers. I think that a lot depends on the engine you pick and where its sweet spot is. Not sure if the other manufacturers have these on line too.

 

[atgreene]

Excellant! I was hoping someone could point me in the right direction. I just need something to throw in the rfp specs. Thanks.

 

[Ford LT-9000]

The truck dealer that you deal with can spec you out a truck to what ever you need. With new engines with the power band so low and you want a automatic. Myself if I was going with a automatic it would be a Roadranger automatic not a Allison. A fuller autoselect is your best bet they are being used in fleet trucks with decent success.

As for brand I would probably stay away from International. Freightliner or Sterling is one of your better options. The VHD Volvo doesn't offer much options either.

I imagine you will want to spec a truck with 46,000lb rears with double locks with a chalmers suspension.

If you go with Cummins power the ISX rated at 450hp will be a good option. The 8v92 you guys have now is rated at 475 but it has only about 1200-1300ftlbs of torque.

If you go with Freightliner or Sterling I don't think Cummins is a option but you always could go with the C-15 Cat rated at 550hp. It will cost a little more but you will have a good truck.

What engine you do choose make sure you have a good engine brake you will have lots of weight on that truck. You will have approx 26,000lbs of water plus the weight of the tank and pump gear. The truck will be easily grossing 58,000lbs or more.

I was talking to a employee of one of the utility companies the other day they are not impressed with International. The trucks they have are 7400 Internationals. The company I work for was looking at crane trucks they looked at International and ended up going with Sterling it was a better truck.

Sterling or Freightliner may not have the quality built cab like a Kenworth or a Pete but they have the good engine and driveline options. The driveline and frame is no different in strength compared to a T-800.

Here is a link to autoselect 18spd

http://www.roadranger.com/Roadranger/productssolutions/transmissions/autoshift18-speed/index.htm

 

[atgreene]

Thanks. The Volvo may come into play due to the fact the town just bought a Volvo wheeler last fall. They hate the freightliner, so that is out. Getting all the towns trucks to one manufacturer would be easier on the mechanic.

 

[Ford LT-9000]

Well if they want to go with Volvo what about going with Mack which is part of Volvo and sometimes sold on the same lot.

Problem with Volvo you only have the Volvo engine option and in the VHD trucks they only offer a 13 litre engine with 485hp.

Here is a adobe filehttp://www.volvo.com/NR/rdonlyres/EF1EAFE6-3CDD-4329-8007-8CCED8341D91/0/VHD_Dump_Spec.pdf

 

[alco]

When we were spec'ing out our trucks, we were always told to tell the apparatus manufacturer what you wanted the truck to do and write that into the specs instead of spec'ing out what you want the truck to have. That way, it is on the manufacturer to set the truck up right. If it doesn't do what you spec'd it to do, they have to fix it on their own dime. But if you spec it out as to what you want on the truck, you're on your own.

Brian

 

[Orchard Ex]

Myself if I was going with a automatic it would be a Roadranger automatic not a Allison. A fuller autoselect is your best bet they are being used in fleet trucks with decent success.

Not trying to be a nit picker but the RR is an Automated transmission not an Automatic transmission. The autoshift still has a clutch pedal to use when stopping and starting, the ultrashift clutches for you, so there are only 2 pedals. It's still a geared transmission, but Otto does the shifting.
The Allison is a more traditional automatic transmission where you get the slip/torque multiplier effect (maybe not technically correct in my terms here?).
People swear that the automatic will get stuck less because you can slowly add power until the wheels almost spin, but not quite, which should be the most traction available. The RR Ultrashift and Autoshift give the road running efficiency of a standard geared transmission without all that messy learning to shift stuff.
I'd think that for a fire truck you'd want the Allison, but I don't really know.
Have fun playing with the specs!
On edit: Brian makes a good point. I'd bet that the truck company's will do most of the homework for you. Sounds like you have already started asking around as to what other stations have that is or isn't working for them.:thumbsup

 

[Dozer575]

I would not use something like that Roadranger in a fire truck. Like orchard says its just a manual crash box that is shifted by a computer.
You need a true automatic transmission, there are all kinds of choices.
Cat even makes them http://ohe.cat.com/cda/layout?m=136641&x=7
Then of course Allison, and ZF. Automatics are as strong or stronger than any manual or constant mesh type gear box. The only down fall is the electronics but then the roadranger has that too. Planetary/torque converter multi disk clutch automatics are tried and true. Huge off road dump trucks use them, huge dozers use them (called power shift transmissions), I don't think there are any super heavy duty applications that use something like that roadranger.
Also with the manual type transmissions in high time situations, the shift collars and splines, dogs or what ever you wish to call them wear at a slight angle or helix, and then they like to pop outa gear under a load. That is not possible with a planetary automatic transmission.
And then you have the torque multiplication with a torque converter on top of the gear ranges, smooth starts, and with lockup clutches the effciency will meet or beat the manual style crash box. How? the crash box has its gear sets churning heavy oil all the time. Most automatics have a variable displacement pump, as well as the direct drive torque converter bypassing TC clutch, so in essance they do the same as the manuals do or better efficiency wise.
You will have the most choice of ratios with the automatic transmission, because of the TC.

 

[nedly05]

Our tanker is a 4400 international with a 330HP DT-530 motor, it has the allison 3060 tranny with 5:38 gears. It is geared too high, we can run 72 MPH and it dies in the hills. The other FD in town has the same truck same specs (except it has 200Gals more water and the DT-570 still 330 HP) The other companys tanker has way more pulling power in the hills and tops out at around 62-65. That truck has 6:14 gears. I drove it myself, and it is a very noticable difference, enough so that we are considering doing a gear swap.

 

[Ford LT-9000]

If the heavy haul guys are using the 18spd autoselect its got to be good enough for the 140,000lb loads. The reason why I said autoselect is its cheaper to fix than a Allison that will cost you 2 arms and a leg to fix.

If they want Volvo then they have a 12spd automatic.

Also spec the water wagon to the spec's the firedept wants and the chassis they want. The local Volly Firedept has bought 2 new trucks through the upfitter that builds firetrucks. Well they only use Freightliner and the dept isn't impressed with the M2 single axle (35,000lb). Both trucks have alison transmissions they are not impressed with them. The one truck is powered with ISC Power I'am not sure what the other truck is powered with.

The 2nd hall has a Ford Cabover not the old style but the Cargo cab but that truck is better built its powered with ISC power its heavy its pushing 37,000lbs.

The hall didn't want Freightliner chassis but they were forced into it.

A water wagon really isn't a hard truck to build. Choose a good vocational chassis send it to a upfitter have the body built. Have a truck with good power etc so its enjoyable to drive instead of the GMC General they have now :lmao

 

[Dozer575]

Ford Lt, why are Allisons more expensive to fix?
Parts cost???

I know the old roadrangers are horrible to work on, well by yourself anyway, I did it years ago, with no help to lift stuff. Timing the countershafts was a thrill. Would rather the Allison to work on.

 

[dumptrucker]

Our fire dept has all allison automatics. They have never had any problems with them at all . I live in a town that is in a valley, everything goes up, steep hills. Gotta remember that fire trucks aren't out pounding the pavement everyday. We have got a kenworth tanker/pumper that is an 86 it's got less than 20,000 on it . never had a problem with trans.

 

[Ford LT-9000]

I was reading a trucking magazine today they did a test drive with Volvo's new 12spd automatic. The only problem is they are not available yet with any other Volvo engine but the big 16 litre and its not available in the VHD chassis that you make a water truck from.

How many miles a year does this water wagon see ?

Are the drivers that bad that they can't shift a manual transmission ?

If you have a X amount of dollars to spend if you spend a big chunk of money spec'ing the truck with a Alison auto that will cost significantly more than a roadranger. So now you don't have that money to upgrade the truck say with a more top of the line interior or shiny stuff on the truck to make it look good.

I checked the Allison website the heaviest automatic they have is only a 7spd ment for emergency truck use.

Choose what ever suits your needs my take on it with the new engines that pull the best at low rpms I would go with more gears. A 18spd autoselect with 500hp engine would make the truck pull any grades at a good clip. If you needed extra water capacity you could have a 3 axle tank trailer to pull behind the tank truck.

 

[atgreene]

A standard is out. It isn't worth putting a standard in a fire truck nowadays. Asking a volunteer to try to learn to drive a standard in a $250,000 truck that they need to respond code 3 with while talking on a radio, watching for other drivers and manuvering through fire scenes is dangerous.

I have driven trucks my entire life and when the siren and lights are going, the two-way radio is blaring and you need to watch for everyone else on the rode, it's best to keep things simple.

Also, we need to be able to mate this up to a 1250 gpm pump/transfer case, so it has to be a typical transmission that the manufactures routinely work with.

The truck will only see a couple thousand miles a year, part of that while pumping, as it turns the odometer while pumping. We definitely don't want chrome or bells and whistles. I would rather put the money into fire equipment for the truck. I've always said that chrome never put out a fire, but add another crosslay or nozzle instead of paying for chrome, now you have done the best for the taxpayers.

A trailer is definitely out, as we need to be able to manuver on small roads and driveways. I would love to do a tractor trailer combo, but we just don't have the space for it to manuver. I've seen some, and they are awesome water haulers.

I talked to the dealer today, he's looking at a Pete, Freightliner or IH. Those three apparently meet the new emissions and will still have room for the NFPA required upfits that are required. Part of the problem fire apparatus has is that it needs to pump it's maximum capacity for 3 hours while all electrical loads are on. Lots of trucks tend to overheat while sitting still working the guts out to turn a pump.:Banghead Limits our options some, but at least we know it will perform when everything is at it's worst.

I like the idea of a Pete, but I'm not holding out hope for it. They make a sweet looking fire truck.

 

[Countryboy]

I like the idea of a Pete, but I'm not holding out hope for it. They make a sweet looking fire truck.

Man, I don't get to see many of those around here. The ones I've seen were super sharp looking trucks. You gonna post pics if you get it right....:drinkup

 

[Ford LT-9000]

I would be pushing for the Pete or a Kenworth I don't know if you really want cornbinder. A KW T800 Chassis would be a good truck to start with and would last forever.

 

[fireman050]

what kind of lighting package are you going with i would suggest fed sig led lighting

 

[atgreene]

It'll be all LED, for sure.

Neighboring town has a KW, sweet looking tanker. I'm waiting to hear back where the manufacturers come in on price as far as chassis. They all will be around 110k or more for what we want.

 

[CM1995]

I have been pricing chassis for a new hook lift truck for our roll-off company. An '08 Mach CPT713B, which is the setback axle, with MP7 405HP, 20k front and 46K rear, 4500RDS Allision auto and normal goodies on the inside and outside runs $117K with FET. A Sterling with similiar specs will run about $108-$110K. Atgreene- being a VFD do you guys have to pay the 12% FET? The prices above are with FET.

I have two 4000 series Allisions in a tandem and tri dump truck. Also have one in a roll-off. I have had the tandem for 3 years, enduring heavy work and not one problem. I totally understand the auto in the fire truck - for the same reasons I have them in my dumps/roll-off except without the whole "somebody's house is on fire emergency" going on - which only adds more to the mix. As far as Allision transmissions being expensive to buy, they only add around $7k to the price. Allision has some aggressive deals at certain times of the year - be sure and ask about those with your dealer. Also you can get an extended warranty very reasonable.

After shopping for trucks, my few observations are this: The KW's are expensive and the cab is just too small, the Sterling is a cheap truck to buy and a cheap truck, I own an International 7600 and will never own another, in our neck of the woods Freightliner does not care about the vocational market, Pete's are just too expensive and Volvo has a "take what's on our lot" mentality. I currently have an '07 Mack granite tri, an '06 Mack roll-off and are looking at getting another '08 Mack hook-lift.

Now I am not a "Mack guy" - it's just the best I have to choose from in my area. The Macks may all crap out tomorrow and put me back on my feet again.

A 500HP wth an Allision geared low should pull the world. I would suggest gearing above the 6 ratio range since you guys don't need high speed and need the power. Good luck in your quest - there is nothing like spec'ing a new truck. It's the closest thing in the adult world of going back to the toy store.