We have long been accustomed to tow trucks for parking violators - they can be found on the streets of any city. But a tow truck for a tank is a more exotic vehicle and is used primarily for delivering tanks to their deployment locations. The M25 was one of the most interesting models in this genre.
Pacific Car & Foundry Company has changed names and headquarters many times. Founded as the Seattle Car Manufacturing Company in 1905, today it is known as the Paccar Corporation, which owns the famous Kenworth and Peterbilt brands. The company closed its own brand Pacific many years ago. In addition to trucks, the company has built railway equipment at various times and made a lot of money from army contracts, in particular, in the production of tanks.
By the beginning of the war, the army monopoly producing military trucks was the Diamond T company (there were a lot of them in the USSR - delivered under Lend-Lease and even partially assembled in the Union). The line included the Diamond T 981 Tank Transporter, which was actively produced and put into service in 1941. Shelvoke or Drewry semi-trailers were attached to the T 981, and this whole structure could carry tanks weighing up to 30 tons, that is, light. Transporting heavy tanks remained a problem. Pacific decided to squeeze into this niche.
The M25 Tank Transporter appeared in 1943. The Pacific semi-trailer was ordered externally from the Detroit-based Fruehauf Trailer Corporation, and the design of the tractor was ordered from another firm, the Knuckey Truck Company. The machine was equipped with a 240-horsepower 6-cylinder Hall-Scott 440 engine. The armored cabin accommodated 7 crew members. Interestingly, the designation M25 refers specifically to the combination "tractor + semitrailer", separately these two elements were designated as M26 and M15. During wartime, joint production was very common - it was profitable for companies to cooperate for the sake of a government order, and not try to do everything alone.
Since 1943, Pacific produced tractors, and Fruehauf - semi-trailers. After the war, a civilian version without armor was developed - the M26A1, which was produced until 1955. The next army contract for a tank tractor was received by Mack with the Mack M123 model.