Interesting similarity but I think the only thing in common is the method of spreading out the gripping force along the cable or umbilical by using the tracks to apply the tension in-line.
"The picture at the bottom shows the tensioner/injector actually pulling something, maybe testing the strength of the injector?" I think that was the actual load test for the tensioner. Notice the cable is "bar taut".
Over the past several years, the company has used tensioners in different projects. They used a tiny tim tensioner to hold an umbilical on deck referenced in this post #msg-27306359 (the photos are missing from the original site, and the board copy is hosted at fotothing, which was down all day}
They also used a large blue tensioner (10- 20 tons maybe) in the court yard on that 3 inch diameter yellow tubing. That was back when we had only basic blurry security cameras for screenshots but they are posted somewhere here.
Also last year the company had access to a 30 ton Barrick tensioner for some project they did.
Pipe laying ships use huge tensioners to prevent the miles of pipe from slipping to the bottom while they are building them on ship.
The one DPDW built looks like it has a special purpose, but just what that might be, nobody has said.