Broken-Down RHTT train

[Bovverboy]

The Bolton to Blackburn line was blocked for about an hour this morning due to the following working coming to grief somewhere around Entwistle.
https://www.realtimetrains.co.uk/train/H11155/2019/10/11/advanced
Delay attribution refers to it as an RHTT, so I presume that's what it was. Luckily, I suppose, this was prior to the start of the day's public service on the line, but the following 0536 Manchester Victoria - Clitheroe was held at Bolton for just over half an hour, then cancelled Blackburn - Clitheroe - Blackburn.

 

[father_jack]

3S08. Broke down inside Sough Tunnel near Darwen. I believe this RHTT is a MPV (multi purpose vehicle) type rather than locomotives.

 

[Bovverboy]

To make a point of showing my ignorance, would the MPV in question have been in use as a water-jetter, or do things such as weedkilling trains also count as RHTTs? I presume a rail grinder wouldn't travel at service speeds, and would only be used inside an engineering possession.

 

[pdeaves]

To make a point of showing my ignorance, would the MPV in question have been in use as a water-jetter, or do things such as weedkilling trains also count as RHTTs?

Most likely jetting. Weed-killer trains are (or rather, can be) the same physical MPV (multi-purpose vehicle) with different modules used at a different part of the year.