Other posts in the Forum have touched on various topics re Sheffield buses, however, what younger members may not know, was during the P.T.E. days, lots of experiments were conducted, at ratepayers expense it has to be said, on environmently friendly projects. Electric battery buses were tested, one of these was used for a while on the City Clipper, it was built by Morrisons, the same people who made milk floats! it had a ton and a half of batteries under the floor wired in series. There was also a Leyland National fitted with an electric motor, this towed the battery pack behind in a special trailer, the idea being, when the batteries were getting low, the pack was simply exchanged for a charged one, thus keeping the bus in service.
One of the best buses to drive was the Leyland double decker that had a Rolls-Royce six cylinder ex army petrol engine fitted converted to run on liquid gas. It was not too sucessful because it did not carry enough gas to do a days running, but it went like s**t off a shovel.
Another strange hybrid was a Dennis trolley bus with a small Diesel engine so it could run a short way off track, this was in Doncaster. Oops! no space left!!!

Find some space. Would like to hear some more!!

I used to like those SYT double decker buses that had a front door for getting on and a door further back for getting off.

Some extra bits of info, most people will have travelled on single deck buses that lower the platform to allow prams and the elderly to get on and off easily, what they may not know, is that this was a Sheffield invention, it was first used on the Leyland National buses, as the air suspension was modified to allow a valve on the front nearside suspension to deliberatly leak, and thus it "sat down" at that point. Closing the valve allowed the air compressor to bring it back up before moving off.
It was widely advertised at the time as the "kneeling National".
I believe it was patented by the P.T.E. I wonder if they still get anything for this?

Malc, would I be correct in saying that, because of the geographical features of Sheffield, (hills and more hills) new types of buses are or were tested out here before going on general release, so to speak?

Or have I been dreaming?

Yes, you are right Sam, most manufacterers in the 70's knew that the hills in Sheffield, plus large numbers of people using buses, would test their designs to the limit, and not just running empty, but with a full load. Any bus driver will tell you that a double decker full, was a very different beast to handle than an empty one. Of course, nowadays, the number of firms making buses has dwindled to about three!

There is still the odd double decker with middle doors running round on TM Travel services like the 293 - they got them second hand from London.