If I'm not mistaken the inspection carriage is applying ultrasonic transducers to the rail top and measuring the reflections. A fracture or crack will reflect back in a shorter time than a signal that goes all the way to the bottom of the rail. Water - and maybe some kind of lubricant? - is used to ensure good coupling between the transducer and the rail and reduce wear - hence, I presume, the water wagons. Nice.
If I'm not mistaken the inspection carriage is applying ultrasonic transducers to the rail top and measuring the reflections. A fracture or crack will reflect back in a shorter time than a signal that goes all the way to the bottom of the rail. Water - and maybe some kind of lubricant? - is used to ensure good coupling between the transducer and the rail and reduce wear - hence, I presume, the water wagons. Nice.
Never heard an 071 go up through the notches quite so quickly, nice! 0:40
This loco (073) had an issue with the engine speed governor or the load regulator apparently at the time and would do this from time to time.
It's safe to travel on trains again as that Covid-19 is no more.
Ahh yea, its grand.