Skagit BU-90 on Tillman Power Trailer
In the late 1960's and early 1970's, many loggers were making the transition from diesel yarders on wooden sleds (used with wooden rigged trees) to steel towers. Most loggers were broke or near broke most of the time, so they were looking to take thier diesel yarder off the sled, and mate it to a steel spar- Skookum/Madill and Berger were the most popular option. They would build a steel tower and carrier to fit your yarder, whatever it was.
On Grays Harbor, at Aberdeen Washington, a machinist/fabricator named Jack Tillman cashed right in on this, and soon was building steel towers and carriers for all sorts of yarders people had locally. And Jack wasn't scared, either! He built some of the biggest yarders ever, and added drums or whatever was needed to your yarder. Or Cat- he added lots of steel towers to Cat D7's, D8's, and D9's with Carco or Hyster drumsets on them. Or IH, Allis Chalmers, or whatever you had around.
One of Jack's specialties was a self-propelled tower, with a gooseneck and dolly, like a trailer. The rear axles were driven, and the dolly was steered hydraulically for off-road moving. On the highway, the drivelines were disconnected, and the dolly removed for towingby gooseneck with a lowbed tractor.
These were often huge monstrosities, and Jack liked building 120' towers with 10, 11, and 12 guylines. Super heavy, super clumsy, super Tillman!
Below is a good example of a Tillman! Skagit BU-90 standard highlead hoist, mounted on the Tillman power-trailer, with big STEERING rear axles. Jack like steering on both ends of the rig for tight corners. Hyd steering removeable dolly seen also. The tower wasn't around, but was a 110' telescoper with 10 guylines as you can see.
What a beast! Photographed at TJ Spradlin's place in the late 1980's.