HMS Howe speed

[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 ?

[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...

[dunmunro]

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...

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.

[alecsandros]

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 ?

[dunmunro]

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.

[Pandora]

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

[alecsandros]

...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 .. ?

[dunmunro]

...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.

[alecsandros]

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 ?

[dunmunro]

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.

[alecsandros]

Ah, ok; thanks

[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...

[dunmunro]

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.

[alecsandros]

Ah, oh; thank you..

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

[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