QE2/Paxman Emergency Generators

[skilly56]

From memory, the requirement is for passenger vessel emergency generators to have fuel available for 36 hours continuous running. On cargo vessels this requirement is for only 18 hours continuous running.

For QE2, Paxman supplied two stand-by emergency generator sets, each driven by a naturally-aspirated 12RPHZ Series II engine (noisy damn things they are too!). The sets are located high in the hull, at the stern, under the swimming pool. The engines have radiator cooling which allows the sets to be used even when the ship is in dry dock.

As at 2008 the engines were still regularly tested and in good order.

The emergency sets were built under Paxman Contract Nos 58913 and 58914 (Engine Nos 650036/1 and /2) and dispatched on 19th April 1967, not long before QE2 was launched. The sets were built on a bedplate, similar to Paxman's industrial generator sets, and had AEI alternators, rated 350 kW at 1,200 rpm.

Skilly

[Rod]

EXTREMELY NOISY!!!!!!!!!!!!!!
Could be battery started or air started.

[Clydebuilt1971]

Do photos exist of these beasts I wonder?

Gav 

[skilly56]

Hi Gav,

I waited to see if anyone else had photographed these animals, but it doesn't appear so.

I have added below a couple of photos I took in 2008 of the 8RPHCZ model (this has 4 cylinders fewer than the QE2 item, so is a V8, not a V12, but has a Holset turbocharger fitted to boost the noise and power! And also a charge air cooler - that's the 'C' & the 'Z' in the model number).

These machines are a bit of a bugger to work on - they have fork & blade connecting rods, same as a Rolls-Royce Merlin, but you only have those little crankcase door openings to get your arms through when trying to pull down or reassemble. All very fiddly to play with at survey time.

Just got to hope Rod doesn't have recurrent nightmares after seeing these photos
These two machines are on a Dundee-built ship that I did 12 years on (1979 - 1991), then briefly went back relieving on in 2010.
(And rejoined again from 2015 to end of March 2017. 1 turbocharger finally failed on the Port machine, after 37 years of operation!).

There are two blocks of four cylinders on the machines in the photos. Just imagine three blocks of four cylinders for QE2's Paxmans.

Skilly

[Rod]

Fortunately I only had to do minor work on them....but I still hated them! Especially if you were getting a hamburger on deck and you heard them start!

[June Ingram]

Wow !  Thanks, Skilly, for posting them and for the commentary.  How large (dimensions) are the V8s and V12s and do you know sound in decibels ? Rod, how long did it take you to respond if and when you heard them start ?  June   

[skilly56]

I vaguely seem to recall (there is a lot of mechanical rubbish in my mental storeroom!) that these V8s were around 5.0 metres long (from the engine oil cooler at one end to the exciter casing on top of the alternator at the other end) x 2.2 metres high to the top of the Holset  turbocharger. QE2's machines (V12's) would have been probably 0.4 - 0.5 metres longer, but lower in height as they didn't have the turbos fitted.
Cheers
Skilly

PS - Thinking about this - QE2's machines would have been about 1.0 m metre longer than the machines in the photos - because of the radiator core & fan assembly. This arrangement would have also made the fuel pumps extremely difficult to get access to as they are on the free end of the engine.
Skilly
30.06.15

[Rod]

Wow !  Thanks, Skilly, for posting them and for the commentary.  How large (dimensions) are the V8s and V12s and do you know sound in decibels ? Rod, how long did it take you to respond if and when you heard them start ?  June   

Well as the space was locked, you hoped that someone was on the way with a key!  Open the air vents, and hope. Couple of minutes.
Then a leccy would arrive with the key.

[June Ingram]

Thanks, Skilly and Rod !  Impressive on all counts !

[Clydebuilt1971]

Thanks for the photos Skilly - always love a good machinery space photo!!

Gav

[Roy Warrender]

Hi any one know where the exhausts of the Paxmans were routed to the outside world

[Rod]

Port and starboard side between2 and 1 decks. ie deckhead of 2 deck

[Roy Warrender]

Hi Rod Do they look like Car exhaust pipes with muffler Boxes

[Rod]

Essentially, yes.

[June Ingram]

EXTREMELY NOISY!!!!!!!!!!!!!!
Could be battery started or air started.

Did they have to be started manually ?  or did the battery or air start hinge on a certain event at the point of loss of power ?