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HMS Howe speed

Posted: Tue Jan 03, 2012 2:21 pm
by alecsandros
Wikipedia Howe page has:

speed: 29.5 knots (55 km/h)

http://en.wikipedia.org/wiki/HMS_Howe_%2832%29#Design

Any idea where this comes from ?

Re: HMS Howe speed

Posted: Tue Jan 03, 2012 5:27 pm
by Pr.Eugen
In "British, Soviet, French and Dutch Battleships of World War II" by W.Garzke & R.Dulin - 27,5 knots at 112930 hp (42530 t)

May be in Wiki we see data from the project alternatives... :cool:

Re: HMS Howe speed

Posted: Tue Jan 03, 2012 9:05 pm
by dunmunro
Pr.Eugen wrote:In "British, Soviet, French and Dutch Battleships of World War II" by W.Garzke & R.Dulin - 27,5 knots at 112930 hp (42530 t)

May be in Wiki we see data from the project alternatives... :cool:


Prince of Wales' "...main machinery steamed at overload powers of 128,000 to 134,000 shaft horsepower with no difficulties..."
G&D, Allied Battleships of WW2, p206

PoW's log also recorded speeds of 29.1 knots just prior to intercepting Bismarck, and I have posted the excepts on this board.

Re: HMS Howe speed

Posted: Tue Jan 03, 2012 9:12 pm
by alecsandros
dunmunro wrote:
PoW's log also recorded speeds of 29.1 knots just prior to intercepting Bismarck, and I have posted the excepts on this board.

We know about that Duncan.

But what about Howe's 29.5 ?

Re: HMS Howe speed

Posted: Tue Jan 03, 2012 9:29 pm
by dunmunro
alecsandros wrote:
dunmunro wrote:
PoW's log also recorded speeds of 29.1 knots just prior to intercepting Bismarck, and I have posted the excepts on this board.

We know about that Duncan.

But what about Howe's 29.5 ?


The two ships have the same machinery, and there's no indication that PoW was at her maximum speed; lightly loaded Howe should be able to achieve 29.5 knots The design specs for the KGV class were 125000shp and 29.25 knots at light displacement. In 1937 Warspite achieved .748 lb/shp. Using the same figure for the KGV class predicts a maximum of ~144000shp at 48 tons/hr (maximum fuel rate). Of course late war, with higher displacements, and in tropical waters these speeds would not be achievable.

Re: HMS Howe speed

Posted: Tue Jan 03, 2012 11:58 pm
by Pandora
alecsandros wrote:Wikipedia Howe page has:

speed: 29.5 knots (55 km/h)

http://en.wikipedia.org/wiki/HMS_Howe_%2832%29#Design

Any idea where this comes from ?

dont know where it comes from.
the wiki is good but you have to remember that anybody can edit the information there.
the pages of the PoW and DoY give a speed of 28.3 knots
the page of the KGV 28.0 knots (1941 trials)
the page of Anson 29.25 knots

Re: HMS Howe speed

Posted: Wed Jan 04, 2012 6:43 am
by alecsandros
dunmunro wrote: ...Of course late war, with higher displacements, and in tropical waters these speeds would not be achievable.

Howe displaced more than the previous KGVs. But maybe some modifications were done to the machinery .. ?

Re: HMS Howe speed

Posted: Wed Jan 04, 2012 8:40 pm
by dunmunro
alecsandros wrote:
dunmunro wrote: ...Of course late war, with higher displacements, and in tropical waters these speeds would not be achievable.

Howe displaced more than the previous KGVs. But maybe some modifications were done to the machinery .. ?


There were some minor machinery variations between Anson, Howe and the first 3 KGVs, but I suspect that Howe's lower trials speeds are also a function of the poorer quality fuel the RN was using in 1942.

Re: HMS Howe speed

Posted: Wed Jan 04, 2012 10:49 pm
by alecsandros
dunmunro wrote:There were some minor machinery variations between Anson, Howe and the first 3 KGVs, but I suspect that Howe's lower trials speeds are also a function of the poorer quality fuel the RN was using in 1942.

That's very probable.
I never understood why the RN was using lower quality fuel though ?

Re: HMS Howe speed

Posted: Thu Jan 05, 2012 2:25 am
by dunmunro
alecsandros wrote:
dunmunro wrote:There were some minor machinery variations between Anson, Howe and the first 3 KGVs, but I suspect that Howe's lower trials speeds are also a function of the poorer quality fuel the RN was using in 1942.

That's very probable.
I never understood why the RN was using lower quality fuel though ?


For a variety of reasons, including increased demand for avgas and diesel, the refinery process was extracting more of the lighter portions of crude oil and leaving a much higher viscosity remnant to be used for bunker fuel. This thicker fuel had a higher capacity to absorb sea water and had a higher proportion of unburnable particulates, and caused increased boiler maintenance at the same time, to remove the resulting deposits.

Re: HMS Howe speed

Posted: Thu Jan 05, 2012 6:31 am
by alecsandros
Ah, ok; thanks

Re: HMS Howe speed

Posted: Thu Jan 05, 2012 8:14 am
by alecsandros
It's OT, but we're having the discussion about kamikaze's on the hypothetical engagements:

Do you have some info about the way Howe and Anson AA batteries performed in the Pacific ? I would expect them to be quite good, with all the improvements received in 1943-1944...

Also, a comparison between USN battleships AA effectiveness and RN battleship AA effectiveness would be very interesting...

Re: HMS Howe speed

Posted: Thu Jan 05, 2012 9:17 am
by dunmunro
alecsandros wrote:It's OT, but we're having the discussion about kamikaze's on the hypothetical engagements:

Do you have some info about the way Howe and Anson AA batteries performed in the Pacific ? I would expect them to be quite good, with all the improvements received in 1943-1944...

Also, a comparison between USN battleships AA effectiveness and RN battleship AA effectiveness would be very interesting...


The RN faced a comparatively small number of attacking aircraft, from both conventional and kamikaze attacks. Consequently they seldom had "free-fire" situations where any aircraft could be considered hostile as typically the CAP outnumber the attacking aircraft. They did shoot down a small number of kamikazes, but the greatest problem was always identifying aircraft as hostile in time to engage them effectively, and the number of aircraft engaged and shot down were probably not large enough to draw any statistical comparisons. Howe, IIRC, was actually the first KGV class BB to join the BEF/BPF. Anson was slated to join the BPF but the war ended just as she arrived, which was a pity as she had the most up to date RN BB AA outfit.

Re: HMS Howe speed

Posted: Thu Jan 05, 2012 11:56 am
by alecsandros
Ah, oh; thank you..

I would expect good results, as the actions in the Mediteranean showed good results of battleship-mounted AA...

Re: HMS Howe speed

Posted: Fri Feb 10, 2012 3:20 pm
by delcyros
For HMS HOWE, some data can be extrapolated on her speed with aviable data.

used data:
fuel consumption trials (clean bottom, temperate water), two data points:

016150 SHP = 16.0 kts
066000 SHP = 24.0 kts

in addition to that, various data from speed trials can be included, additonally, I have included the data from DoY, ANSON, KGV and PoW, which gives a scatter of datapoints:

112900 SHP = 27.5 kts
111700 SHP = 28.0 kts
110000 SHP = 27.6 kts
113000 SHP = 27.7 kts

in addition to these, fairly robust data, I have also included a claim of PoW that it achieved 29.1 kts at 134,000 SHP (overload) acc. to her pitlog at unknown displacement.

With these data, it was possible to normalize (averaging) them and find a best fit curve relating speed in kts to SHP (see attachment).

hope, this helps,
delc