Talk:Lap Engine

Type

Andy, I'll leave this in your capable hands. Just curious why it's not linked as a Watt steam engine ? Widefox; talk 14:41, 13 March 2015 (UTC)

Firstly there's not really any such thing as a "Watt engine". He didn't sit down one day and invent an engine. He progressed in multiple stages, developing from previous ideas (his and others) and each stage stands alone as an improvement to what was there before. So which is the "Watt engine"?

Secondly, if there has to be "a Watt engine" then there are two changes that make more of an impression than the others: the separate condenser and the rotative engine. The article at Watt steam engine (as is typical for most coverage of Watt) emphasises the condenser and somewhat ignores the rest. The point about the Lap Engine is that it's the first fully developed Watt rotative engine, with all the crucial parts in place. There are surviving engines that demonstrate the early Watt engine much better than this, this engine is best used to clearly illustrate the rotative aspect.

Yes, I'm one of those that sees the Lap Engine as older than the Whitbread Brewery engine. Whatever the Whitbread looked like and whenever it was first erected, many of the parts on it today are somewhat later and more developed than this first example. As for almost any beam engine, they lasted a long time and especially the early ones were around at a time of considerable development. Few Georgian engines resemble their original design in all the fine details. Andy Dingley (talk) 15:31, 13 March 2015 (UTC)

Sure. Doesn't that mean it's even more a fully fledged Watt Engine than earlier ones though? Does the Kinneil Engine have a separate condenser? The nav template is using Watt as "Operating cycle", so emphasising the separate condenser. Interestingly, in the Whitbread Engine emphasises four Watt improvements, which I endeavoured to put in the template. From briefly looking at this, the operating cycle seems to be one of the dominant issues for the generations due to efficiency, with much retrofitting. Cornish is another one - on the nav I put it as a sub-type of a compound, but didn't double check it. Widefox; talk 12:19, 14 March 2015 (UTC)

There are several Watt operating cycles. There's even one of them that Watt didn't use (high pressure or "strong steam") as he recognised the concept and its advantages, but rejected it as too difficult to make a safe boiler for. Then there's the question of whether Watt used early cutoff, and if so, does that make a distinct cycle?

With a "Watt engine", where's the energy in the transfer from boiler to engine? Is it in the latent heat of vapourisation of the steam (as for Newcomen), and so there's no efficient engine without condensation, or is it mostly in the excess pressure of the steam, and so merely doing work by expansion without condensation can be usefully efficient. Watt built engines for both cycles. Andy Dingley (talk) 15:26, 14 March 2015 (UTC)

All well and good. Still, we include links to both "Watt" and "beam" engines on the earlier engines, but not here. The same (broad scope) logic applies to "type" "beam engine" as the early ones were water not steam. At least if we link both articles we're covering it. Unlinked "Watt" may refer to the person, rather than the type. (we also have Boulton & Watt engine as a redirect to Watt steam engine.) Widefox; talk 12:01, 16 March 2015 (UTC)