I also worked on maintenance at Merseyside Power Station for UML for a few years, up to the end at 1998. When I was there we had 3 servicable boilers, although 1 was never used.
When I was there, we had:-
Boiler 3 - HFO (Heavy Fuel Oil) still there, but scrap
Boiler 4 - HFO still there, but scrap
Boiler 5 - HFO Never used
Boiler 6 - HFO Standby
Boiler 7 - Coal In daily normal use
T2 Turbine - Unservicable
T3 turbine - servicable and in daily use
Engine generator - regularly used
Boilers 5 and 6 had 4 burners each, at 8 gallons/minute per burner
Boiler 7 ran on small grade coal, and was thrown in on 2 rotary feeder from the front on a chain grate.
Boilers 1,2,3,4 had been 650psi on HFO
Boilers 5,6,7 were rated at 100Tons/hour of steam at 1500psi
T2 had been 10Mw, 11kv (1500psi in, 650psi out)
T3 was rated at 14Mw, 11Kv (1500spi in, extract at 230psi, exhaust at 110psi) Gland steam was passed into the 20psi main that was used for tank-farm and domestic heating.
There had formerly been P1, P2, P3 turbines (650psi in, 230 psi out) and S1 and S2 turbines (230psi in, 110 psi out). These had been removed before my time there.
There were 2 small turbines driving boiler feed-pumps, but these were not used.
The engine generator was a Mirrlees Blackstone KV-major V18, driving a 10Mw alternator on 11Kv. It was started on gas oil, but run on S20 HFO (2% sulphur). It had 2 turbochargers and a waste-heat boiler. The waste-heat boiler used to produce about 7-8 Tons/hour of 110psi, and demineralised water for the main boilers was passed through the jacket to act as a pre-heater, saving about 7-8 tons/hour steam. So the action of putting the engine generator on removed about 15Tons/hour of load from the main boilers.
Boilers 5 and 7 were fitted with Bailey DCS controls, and boiler 6 had pneumatic Bailey Miniline500 controllers.
Merseyside power station had Turbine generators on 11Kv, and had formerly had generators also on 3.3Kv. The electric feedpumps were still on 3.3Kv until the end.
Central Power Station had (before my time) condensing turbine generators on 230psi, and later a back-pressure set(230psi in, 50psi out). All generators in CPS were at 6.6Kv, as was the link into MANWEB.
Merseyside power station did not have a "direct link" with MANWEB, but the 11Kv system had a link with MANWEB at Compound Mill Substation, on the Lever Brothers site. Formerly the link was at Sunlight South substation, also on Lever Brothers site.
The 6.6Kv and 11Kv networks had an internecting transformers which were the large transformers just inside Merseyside Power Station main gates. Because of the way that the systems had developed, some customers substations were on 6.6Kv, others on 11Kv.
The 2 links into MANWEB were into their 2 33Kv feeders that ran between CEGB Bromborough, and Rock Ferry substation.
As for Hosemans comments, we knew the place was full of Asbestos. Boilers 1-5 and all of their pipework were asbestos lagged, it was sprayed onto the beams in the boiler 1-4/ areas. It was under the floors like snow, various panels were made of it - it was everywhere. There was a lot of mercury we had recovered from instrumentation, but no doubt there was more elsewhere. There were Igema gauges still in the old boiler house with its own fluids.
I very much enjoyed my time working for UML, and the people I worked with. After closure we all were treated to a day at Leicester races, and 2 nights in a very nice hotel, and return coach travel. UML was one of the best employers I have ever worked for.