Here's a brief history on the man who essentially started the towing and recovery industry, Ernest W. Holmes, and the company he founded, the Ernest Holmes Company, which still exists today.
Our story begins on January 17, 1883, when Ernest W. Holmes is born in Hobbs Island, Alabama.
While Ernest was in business school in Chattanooga, TN in 1916, a fellow student and friend, John Wiley, would have the misfortune of his Ford Model T flipping over into a ditch. At this point in history, "towing and recovery" didn't really exist - if you needed to move a disabled vehicle, some type of impromptu system would be devised, such as a rope or chain hooked to another vehicle; recovery was similar - if your vehicle ended up in a ditch, a rope or chain would be connected to another vehicle, including farm or construction equipment, or even horses or mules.
This obviously wasn't a sustainable way of handling the issue, especially with automobiles becoming increasingly popular - so enter Ernest into the arena. Ernest would take his 1913 Cadillac and modify it by adding a homemade boom and hoist setup, equipped with an iron chain for lifting and pulling (there is a replica on display at the International Towing Museum in Chattanooga). After an unsuccessful first attempt, some quick modifications were made and he successfully recovered Mr. Wiley's Model T - and basically singlehandedly started the towing and recovery industry.
For the next few decades a similar setup would be common for wreckers - take a large, heavy automobile like a Cadillac and modify the body to accomodate the wrecker setup. A staple feature introduced very early on, and maintained until the introduction of hydraulic wrecker units, was the "split-boom". The spilt-boom is hard to explain, but the booms could be disconnected at the ends near the sheaves, and could pivot 90 degrees to the sides and be used for side winching or lifting. The distant predecessor to the modern rotator. I'll give a story example below about this being used.
Holmes would become the premier wrecker manufacturer during the first half of the 20th century, including providing over 6,000 wreckers to the Allies during World War 2. This widespread dispersal and use of the units would be advantageous, as Holmes units would also prove popular in around the world.
Holmes would always specialize in mechanical wreckers, which means the gears for winches and boom movement were driven by chains and shafts, rather than the modern hydraulic systems. They would build everything from light duty to heavy duty wreckers, rollbacks, and even railroad cranes.
Ernest W. Holmes would pass away on June 10, 1945, and his oldest son Ernest Holmes Jr. would become company president.
Throughout the years Holmes would have several notable customers, such as the U.S. Miltary, NASCAR, and Indy Car, all of whom would employ Holmes units for decades.
They would eventually design and build hydraulic wreckers, but by the time these became popular, competition was increasing, and the Holmes hydraulic designs never became as dominant a force in the industry as their earlier mechanical units had been.
Eventually, in 1990, Mildred Holmes would sell the company to William G. Miller, and Holmes would become part of Miller Industries. Miller Industries still exists, and has several other brands in its portfolio in additon to Holmes (but I'll skip Miller history today), and Holmes continues to offer light, medium, and heavy units, though only 1 model in each category.
Check out their website to see the current Holmes offerings (220, 600R, DTU).
We have a few Holmes units in our fleet, one in active service and the others in the historical collection.
The oldest is this: W-10, "Big John", a 1953 International Harvester with a Holmes 850. The chassis is obviously military surplus, but I'm not sure about the bed - whether it was built like this originally, or had the bed added. I've seen one photo of very similar trucks lined up around the time of the Korean War, but haven't relocated that photo (it's in a book around here somewhere) or found any other documentation on it.
6 wheel drive, with a Continental gas engine - top speed around 40.
Anyway, we bought it in 1966, and it was brought into Greensboro on a flatcar by the Southern Railway - not sure of it's history prior to that point. From then on it worked steadily into the late 90's and early 2000's, though by then it was mostly for backup and off-road recovery. It eventually became essentially a retired mascot, but has since become inoperable and in need of a restoration. There's a multitude of stories about "John", but I'll just regale you with one, pertaining to the split-boom section above: John was used regularly for decades by the late, great, Bruce Kirkman, for all types of jobs, but this one comes from pretty early on - he had a car off in a ravine, and took John out to recover it. He decided to use the split-boom capabilty, and swung one of the booms over the side, and preceded to winch the car up the embankment. However, these booms are not able to pivot under load, so he has a car sitting on the lip of a steep embankment, but can't move the wrecker unless he releases the car, which would then fall back into the ravine.
Just so happens that nearby is a friend with a dump truck load of rock - Bruce recruits said friend, and hooks a chain from the dump truck to the car (which was a big Cadillac) to hold it until the wrecker can be repositioned. Wrecker gets repositioned and the job is quickly completed, and a lesson is learned on those new fangled split-booms.

The newest is this:
W-41, a 2012 Peterbilt 386 with a Holmes DTU (Detachable Towing Unit).
We acquired the truck used a couple years ago, and eventually decided to have the local Miller dealer install the DTU.
It's been in service a few months now, and is proving very useful.
We actually had some issues with it immediately after picking it up - namely some incorrect installation problems, which resulted in it returning to the dealer more than once. And they couldn't fix it, even though they installed it...
So we took it to the other local dealer, who distributes the competing brands, and they had it ready to go in very short order, and it's been fine ever since. I won't go into detail on that whole debacle.

Well, that's a brief rundown on the history of Holmes, including some personal anecdotes - thanks for looking!
Very interesting and two great looking trucks there
That’s a lot of interesting history.
Thanks for sharing.