Interesting footage

This is Polish popular-science TV program from 1979 on trucks that includes lot of footage from Britain:

Safety bumpers, pneumatic axles and loads of more. It shows also prototype of modernized cab for Polish trucks Star of the era.

Here another chapter of the same program on trucks from 1982, including some interesting Polish prototypes:

Unfortunately no English subtitles, which is a shame, as these programs were really high quality.

In the 1st Video about 6 mins in, it shows a Quinton Hazell UNDERIDER fitted to a Scammell trailer pulled by a Leyland Marathon. This motor was based at Nuneaton, and at one time was on Colwyn Bay-Nuneaton trunk.
Remember seeing it at Warton at few times in early 80’s
Here is the system

wheeltapper:
In the 1st Video about 6 mins in, it shows a Quinton Hazell UNDERIDER fitted to a Scammell trailer pulled by a Leyland Marathon. This motor was based at Nuneaton, and at one time was on Colwyn Bay-Nuneaton trunk.
Remember seeing it at Warton at few times in early 80’s
Here is the system

I wonder why it didn’t caught up?