1979 Ford F700 Service Truck and Miller Welder

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Ford Shop truck
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Miller Big 40
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Electric Crane

Some sort of a mechanics truck, service truck or what ever you want to call it (with or without a Miller Big 40 welder ) is an absolute necessity for any business where you have to make field repairs. Cars, lawn mowers and chain saws can be hauled, dragged or carried to a shop somewhere for repairs but if you operate or maintain anything that is bigger than that or can't be moved you have to make house calls. All the logging machinery is bigger than that and house calls are the norm. If you want to stay in business as an operator you have to have at least some in house repair capability. If you run newer machinery you may be able to rely on dealer support for major things and handle the situation that way. Our tradition has been to buy orphan machines which have little or no dealer support. Our logic is that these machines are available at very deep discounts in the second hand market so we don't have so much cash tied up in them. The other shoe of this strategy is that you have to have a robust shop truck because if it breaks, and it will, you have to be resourceful enough to figure out how to fix it even though traditional parts channels may be be open.

Now that we know why we have a shop truck, the real question is what a shop truck should look like. The problem up and down the line with shop trucks is that you can't have one that does everything you would like it to. Your dream shop truck is the size and cost of a 4 wheel drive pickup. It has a welder big enough to glue a patch on the side of a battleship in one bead, a crane that will lift the battle ship out of the water so you can apply the patch, an air compressor that will run the biggest of air tools without stopping for a breath, and plenty of storage for all the tools and spare parts that you might ever want. As you might have figured out by now that dream shop truck is only a dream. It doesn't exist.

We've tried a couple of solutions now. Our first shop truck was an old railroad service truck. It was an IH 1600 4x4 From a truck standpoint it has a lot of similarities to the Ford featured here. Also a lot of differences. The IH is a 4x4 with only a 4 speed transmission. By contrast the Ford has a slightly higher GVW rating (19,000 lbs) and has a 5 speed transmission with a 2 speed rear end. This makes it more pleasant to drive on a good road--indeed it is similar to many a U-haul rent a van. When the road runs out and you have to keep on going, of course, the 4x4 does.

The Ford you see here was in its day a US WEST service truck (a regional Bell phone company) which probably explains why it is sort of a fair weather truck. You never find the phone company very far from the highway. This also explains the flood lights built into the side of the tool body.. The interesting thing out this service vehicle is the fact that the service body is set back 24 inches from the cab. This is a fairly uncommon configuration but certainly not unheard of. The problem is the need to accommodate the welder. If you are going to fix things that are broken you gotta have a welder. If you are just a parts changer then maybe not, but real mechanics need welders. The $10,000 question is how big a welder to have. One of the all around favorites in the business is a Miller bobcat. As usually configured this is a 225 amp gas drive welder generator which will produce up to around 8 KW of 110 volt power (if you aren't welding). IT is often seen with an opposed 2 cylinder air cooled gas engine This is a 3600 RPM unit which is small enough to fit cross ways inside a service body. Indeed this is how the Railroad truck was intended to be configured though it came without the welder. The welder went crossways in the front of the truck body and the inside panel on the right was cut out. This way when you open the right front door you can access the business end of the welder and have place to hang your welding leads and extension cord behind the door. Your gas bottles are just inside the back door strapped to the left side.

This works if you have a covered shop truck. Many people prefer open trucks which makes it easier to load and haul things (even though these covered trucks have a sliding roof). With the covered design you get security and protection from the weather but with some trade offs. It is pretty common with shop trucks with the open design to mount the welders, generators, compressors etc up on top of the tool boxes. By balancing them on the rail so to speak this leaves the bed of the truck open for hauling things. What we did with the IH service truck besides stuff the welder in the back, we also stuffed a large gas drive air compressor in the back. By the time you have done that there isn't space for much else.

The designers of the Ford shown here went about things completely differently for a number of reasons. The service body is set back from the cab and the welder is frame mounted between the service body and the cab. For little welder this probably doesn't make sense, but the Miller Big 40 is not a little welder. It features a 3 cylinder water cooled engine and the entire unit is 64 inches long and weighs 1400 lbs. This length means that it won't fit crossways inside a service body which usually proves only 4 to 5 feet of bed width inside (in order to leave room for 13-15 inch deep side compartments on each side within the confines of an overall 8 foot width. As heavy as the welder is you wouldn't want to put it to one side of the truck or it would throw the whole truck out of trim which would not be a good thing. Consequently, building the truck became an issue of installing the welder and building a service truck around it. It is really a 'welder truck' as the welder dominates the design. Indeed we were buying a welder when we bought the truck and the Ford just came with it. The Miller Big 40 is pretty close to a real welder. It is a 300 amp continuous duty cycle machine and will hump up for 400 amps for limited duty cycle. This means that it is happy with 3/16th or 1/4 inch Low hydrogen 7018 welding rod, which implies that if you have hunks of steel an inch or more thick that are buckled, bent and broken you will be ready when Humpty Dumpty needs put back together.

As is customary the welding leads are behind the right front door of the service body, and there is a convenient external box by the end of the welder for the can of gas that you need to carry. The Miller Big 40 is nearly twice the welder of the Bobcat 225 and 3 or 4 times the price. They sell new in the $7500-$10,000 price range, but the water cooled 1800 RPM engine can be expected to last a lot longer than the Onan 2 air cooled 3600 RPM engine.

Then there is the air compressor. Currently a couple solutions are in vogue for the air compressor. Sharp eyed folks will notice the air tank hung up above the welder. At 2001 version of the Oregon Logging Conference (and trade show) I found mostly hydraulic drive compressors. In this design a PTO driven hydraulic pump is installed on the side of the transmission, and a hydraulic motor/compressor combination are stuck on or in the service body somewhere. Alternatively at least one manufacturer offers a vane pump which you can drive off the fan belt of the engine as an extra accessory. The pain of this particularly these days is that under hood space is pretty well taken and getting something else behind abelt pulleyy is easier in theory than fact. This old Ford, however had lots of space under the hood and actually has a V configured compressor (a real monster) belt driver off the front of the engine with the compressor sitting off to the right side of the engine sort of over the frame.

There is just space for a gas bottle compartment on the left side of the truck at the end of the welder. It is vented so the welder cooling fan blows through it as the compartment is in front of the radiator. Taken collectively this means that the Ox-Act, Compressed Air, Welder and generator are all either under the hood or within the first 24 inches of truck frame space and NOT in the tool body. Even the box for the extra Jerry can of gas is in that area. The solitary exception is the right front door which as the welding leads in it.

This means that the inside of the service body is a lot different. Instead of having two gas engines running inside the back of the truck you have none. This service body was equipped with the extra high walk in canopy which provides about 6 feet of head room inside, and was obviously fixed for for having essentially an office in the front of the bed with a small stand up desk, and some paperwork pockets. The canopy is a full width one with a host of close spaced interior shelving above the outside tool compartments. A couple 20 watt florescent lights provide ample interior lighting.

Also of interest inside the back door is a small electric hoist. It is rated at 2000 lbs, and is particularly suited by its location for lifting things into the back of the truck. It is all manual except for the 12 volt electric winch that runs off the truck electrical system. We have found it convenient for providing assistance in changing 14x24 truck tires. Those things are too heavy even for 2 men to man handle.

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