Medium Duty Ambulance FAQ (Freightliner, International, GMC, Chev)

[charlieaarons]

MAN has an option on their medium and HD trucks of hydraulic driven front drive in addition to conventional RWD. Saves the weight of transfer case, front axle. No low range of course. Mainly for occasional 4wd needs like a muddy construction site.
I think one Unicat customer has chosen it for a chassis. Might be good for the archetypal RV “stuck on wet grass”, along with electric FWD. Of course a locking rear diff also helps a lot.

 

[tbone1004]

Looking to buy one of these things for scuba diving and I am running into some issues with payload capacity.
What are you guys seeing as the curb weight for your medium duty boxes before they are stripped?
Also what is the height of the back entry point?
Also also, what are you guys doing for spare tires?

 

[Ozrockrat]

Our dual cab has a GVWR of 25000 and a curb weight of 18000. As it sits now with the big axles, wheels, all setup for a trip including spare it comes in at 22500-23000. That’s with a lot of tools water etc. so plenty of capacity left.

These trucks also come with scuba tank holders which I find useful for cords, hoses and the awning but I am sure you could make better use out of them.

 

[qcdstick]

Mine is a 20k truck (8k front, 12k rear). Loaded with camping gear, parts, supplies for a race weekend it scaled out at 16,620 (7.8k front 8.82k rear) with my wife and I in it. I'm sure you'll be packing a ton more weight in it than we do, but we had 3,400lbs to spare and all of the capacity is in the rear where you want it. Even with the big trailer hooked up we have close to a ton of rear axle cap left for us. We have done little to no stripping of the box beyond removing the unneeded medical gear and loading it up with our stuff.

 

[tbone1004]

@Ozrockrat Thanks for that.

Current plan is a Cargoglide 2200XL where the stretcher would go. Gives a 2200lb load capacity with 100% extension. The O2 compartment will be reconfigured with 4x 4500psi cascade bottles *basically 4 full size welding bottles*, and then one of the side compartments with a big electric booster. This is not for "normal" scuba diving as I am part of an exploration and research team that deals with underwater caves in Florida.
Current plan says about 2500lbs of scuba gear+cargoglide itself, 1000lbs for the fill station, and the better half wants hot water to shower off after we get out of the water since most of the exploration is done in the winter and water weighs a lot.... Grand total has me at about 5600lbs including passengers but not including water and I'd like to have close to 7000lbs to be able to pull a reasonably sized trailer if I have to.

@qcdstick Just saw your build thread which is pretty similar to what I'm hoping to do to this thing. Very minimal modifications though hopefully finding a unit who has a dual compressor for the inboard AC since I can plug in at night.

I've been hunting units for a while and have to be patient since it seems the chip shortage has hurt availability. Prioritizing 10-lug axles and trying to find 21k+ gvwr has made the pickings very slim, but we shall see what comes up over the next 6 months or so. Thankfully I'm travelling a lot for work and summer is the "off season" for this type of diving so I'm hoping I find one by July ish time frame

 

[rlrenz]

Mine is a Medic Master body on a Freightliner FL60 chassis. GVW is 20,000, empty it's at 14,000. When I bought it, we had 1000# of parts loaded on the driver's side for the return trip, but the air suspension kept it level. The loading height is as per the Federal standard, KKK-1822 (Google for a copy) -- the standard requires no more than 34 inches

 

[tbone1004]

Mine is a Medic Master body on a Freightliner FL60 chassis. GVW is 20,000, empty it's at 14,000. When I bought it, we had 1000# of parts loaded on the driver's side for the return trip, but the air suspension kept it level. The loading height is as per the Federal standard, KKK-1822 (Google for a copy) -- the standard requires no more than 34 inches

Thanks! Great news on the weight!!
Not so much on the loading height, but will figure something out. The Cargoglide is going to add 6" to the floor height for the slideout which is going to be a problem putting the doubles on and I imagine the 34" is with the back end dropped, but will see when I get the truck in.

Went through Ozrockrats build thread just now and am in the middle of yours stealing ideas!

 

[qcdstick]

Just ran out and measured mine. Floor at the rear doors is 29.5" off the ground with the bags fully deflated. That would make the inflated height 5.5" taller at ~35". So I would assume then the 34" requirement is indeed bags deflated, but your rig may or may not be a fair bit lower?

 

[tbone1004]

Just ran out and measured mine. Floor at the rear doors is 29.5" off the ground with the bags fully deflated. That would make the inflated height 5.5" taller at ~35". So I would assume then the 34" requirement is indeed bags deflated, but your rig may or may not be a fair bit lower?

Awesome! Thanks for the data point.
Being an engineer I'm trying to have this whole project laid out while I'm looking for the right vehicle and I know it's all too unique by vehicle so I'm trying to gather as many data points as I have to make sure I'm at least on the right path.

 

[rlrenz]

Medium ambulances are designed to collapse the air suspension for loading. The collapse is triggered by opening the rear doors, and generally also by a switch on the driver's console and often by a switch by the rear doors. Installing oversize tires increases the loading height, though.

 

[tbone1004]

Medium ambulances are designed to collapse the air suspension for loading. The collapse is triggered by opening the rear doors, and generally also by a switch on the driver's console and often by a switch by the rear doors. Installing oversize tires increases the loading height, though.

The worst this will ever see is fire roads so I have no real intention of increasing the tire size but it will see them on a regular basis.
The main goals I have in original purchase are a Cummins or Pre-MaxxForce DT466, more than 6k payload capacity, and HVAC that can be plugged into shore power. It severely limits the pool of vehicles, but the shore power HVAC is critical since it will be filled with wet dive gear in the jungles of north Florida. I'll have shore power at night everywhere I go, but really don't want to get into the crazy amount of work to get it to go that you and the Ozzie have had to go through.

 

[qcdstick]

I could be wrong, but I don't think you are likely to find an ambulance set up to run the AC off of 120v. Ambulances only need AC back there when they are in service, and when they are in service the engine is always on so there is no possibility of a non-start. A possible exception are the ones that are garaged in a standby bay (like a fire department) but in that case, you wouldn't need or probably even want AC running in the truck as it would just make the garage hotter where people are likely to actually be.

 

[rlrenz]

Easy solution -- many medium ambulances have a Hoseline AC system, and some have the Hoseline 12/120 AC package. That's a 120 volt AC standby system that's powered by a 30 amp RV connection. I built mine from pieces and added a 3 KW Onan as well.

 

[tbone1004]

Easy solution -- many medium ambulances have a Hoseline AC system, and some have the Hoseline 12/120 AC package. That's a 120 volt AC standby system that's powered by a 30 amp RV connection. I built mine from pieces and added a 3 KW Onan as well.

That part of your build thread is bookmarked!

 

[rlrenz]

Before I found the pieces for a DIY installation, I'd talked to a local ambulance dealer about having one installed. They regularly replaced existing units that were 2-3 years old as a "just in case" preventive maintenance job on ambulances -- they estimated about $2000-2500 for the used AC with installation. Because my unit uses a narrow evaporator, I decided to use a totally separate evaporator instead of their combined unit. Instead of installing a dual coil condenser, I found a used top mount condenser. I found a new compressor on ebay for $100. The compressor, mounting bracket, condenser, and evaporator cost about $500 delivered to MN. I still needed hoses and miscellaneous, but the end result was a new unit for less than half the cost of a used unit.