Hydraulic transmission as 'green energy'?

Apologies if thus has been posted before, but a search drew a blank.

WORK is progressing on DVT No. 82113 at the Bo’ness & Kinneil Railway to convert it into a test bed for a new form of traction. The project, funded by the Rail Safety and Standards Board (RSSB) and Artemis Intelligent Power, will see the DVT fitted with a JCB engine, backed up by hydraulic accumulators that store energy under braking. This energy can then be reused for acceleration, with the idea being to prove whether the technology can be applied to rail use.

https://www.railexpress.co.uk/in-the-october-issue-new-loco-takes-shape/

 

One to keep an eye on. Whether this installation provides enough useable grunt to justify the weight penalty and additional maintenance burden will be interesting to learn. If I'm understanding the aim of the exercise (do please note the 'if'!), the purpose is to overcome the inertia of a train at rest, with benefits in terms of fuel savings and reduced emissions (?). Would a significant reduction in diesel engine noise, under acceleration from rest, be another aim?

To an old fart like myself, the notion of a heritage workshop clearly being regarded as having the expertise (or the space, for that matter!) to perform such work for 'the big railway' is little short of astonishing, plus unquestionably being a real 'feather in the cap' for the B&K's team and their facility.

It's a great indication of just how far the perception of our movement, most especially by some of the 'movers and shakers' within the mainstream rail industry, has come over the years.

 

Interesting idea, the traction motors, and probably any other type of transmission, are sized on maximum torque and maximum speed. Starting generally uses the short time thermal rating of the motor, so any assistance it can receive from a hydrostatic drive will reduce one of the constraints on the design. Recovery of braking energy will be useful too.

 

The concept doesn't appear that different from the Parry People Mover (PPM), in use on the Stourbridge Town Branch Line, except that it uses hydraulic accumulators instead of a flywheel for energy storage.

 

Both posts seem reasonable and logical, but tbh I'm nowhere near certain I've got that much of a handle on this technology yet. The potential for an effectively regenerative kick (with backup power system) at the point of maximum inertia (and maximum mechanical wear, during the time an engine is within it's working temperature range) seems great, but only if the power to weight ratio is OK and the maintenance burden acceptable on any eventual production versions.

I think I've got some catching up to do. Never too old to learn ..... Eh?