There are a couple of preserved class 77s, however. Though we do have several preserved tramways around the country, these are electrified at a lower voltage and at the present time a fully electrified preserved railway in the UK is basically unprecedented. I wouldn't be surprised if the expanded safety case required for volunteer operation around live OHLE would be enough on its' own to scare off most willing to even consider such a notion, let alone the practicalities (and financial implications) of maintaining several miles of overhead line equipment.
Plus, as
Bevan Price sensibly states, by not operating steam locos you are likely to lose a substantial portion of the general leisure market, which makes up a fair proportion of the custom of a typical preserved railway.
With no access to the Woodhead tunnels, I feel that the opportunities for a preservation attempt over a section the Woodhead route are quite limited. Either of the two primary options (Hadfield to Woodhead, or Penistone to Dunford Bridge) would by necessity be short in length - not really long enough to give a suitable run for mainline locomotives or offer an immersive heritage "experience" - and as far as I can tell, on the western portion between Hadfield and Woodhead, which in my opinion is the more scenically notable stretch, there isn't really anywhere that offers the space for maintenance and stabling facilities (There'd be a bit more space available at Dunford Bridge). It's a pleasant fantasy to think that such a preservation effort could extend back to the site of the former steam centre at Dinting, but as this would require access to Network Rail metals there's limited chance of it being anything more than that: While there is a precedent here with the extension of running powers to the NYMR over the Grosmont to Whitby section of the Esk Valley line, the frequency of Northern Rail trains between Dinting and Hadfield is somewhat higher.
Added to this is that either branch, west or east of the Woodhead tunnels, doesn't really "go" anywhere: There isn't anything with a particular tourist draw at the far end of the line that merits making the journey in the first place. This is where lines like the North York Moors, Severn Valley and West Somerset Railways really excel (with Pickering/Whitby, Bridgnorth and Minehead respectively) as well as in terms of their length of journey. I suppose that some lines have managed to make a "go-er" of it irrespective of this criterion: Who really wants to end up in Loughborough, for example?