Stretcher with slide out handles

[Meekumslr]

Hiya all,
If there are any RAMC, medical or stretcher experts out there, I have a stretcher which is the same type fitted to the MkIV ambulance in the Museum of Army Medicine.
The handles of the stretcher slide out from the main body and are retracted when not in use.
Does anyone know if these had a specific use?
I thought it was a way to make use of a stretcher with damaged handles but it’s far more work than new bars plus... why would they need to repair.
The answers out there somewhere.
Neil.

[Meekumslr]

Hello all,
since posting this, I believe I have discovered the reason for the sliding handles.
These stretchers are ‘John Furley’ stretchers, WW1 St Johns Ambulance.
John Furley being one of St Johns Ambulance founders.