Allied Troopships of WW2

[BBfanboy]

ORIGINAL: Ian R

I remember reading somewhere (possibly on here) that when building of merchant hulls was expanded during WW1, they went for the tried and tested reciprocating engines instead of then the then new-fangled turbines. The manufacturers just weren't tooled up for the new technology stuff.

Eventually the EFC set up Hog Islander production, with the new design featuring oil fired turbines - too late for WW1.

Britain used oil-fired turbines in the Queen Elizabeth class BBs, but reverted to standard coal fired reciprocating engines for the R class BBs because the government felt the shipyards/engine manufacturer had overcharged for the turbine engines and Britain did not have easy access to oil fuel. I wouldn't be surprised if heat resistant metals like tungsten and titanium were also in short supply for making turbine blades. Nascent technology always has its growing pains and starts out expensive.

I thought I read somewhere that Germany had a lock on diesel technology during the interwar period because they patented it. So I could see them licensing Italian shipyards for it but limiting how much Britain could use it until at least the mid-1930s.

[Zorch]

ORIGINAL: BBfanboy

ORIGINAL: Ian R

I remember reading somewhere (possibly on here) that when building of merchant hulls was expanded during WW1, they went for the tried and tested reciprocating engines instead of then the then new-fangled turbines. The manufacturers just weren't tooled up for the new technology stuff.

Eventually the EFC set up Hog Islander production, with the new design featuring oil fired turbines - too late for WW1.

Britain used oil-fired turbines in the Queen Elizabeth class BBs, but reverted to standard coal fired reciprocating engines for the R class BBs because the government felt the shipyards/engine manufacturer had overcharged for the turbine engines and Britain did not have easy access to oil fuel. I wouldn't be surprised if heat resistant metals like tungsten and titanium were also in short supply for making turbine blades. Nascent technology always has its growing pains and starts out expensive.

I thought I read somewhere that Germany had a lock on diesel technology during the interwar period because they patented it. So I could see them licensing Italian shipyards for it but limiting how much Britain could use it until at least the mid-1930s.

My understanding (from somewhere in my fuzzy memory) is that a shortage of gear-cutting machines (that are needed for turbines) was the USA bottleneck.

Someone will probably correct me on this, but I thought the R class BBs used turbines from launch; it's just that they were coal-fired in most boilers. The Royal Navy was unhappy with British manufacturers failure to keep up before WWI. They couldn't do 'geared' turbines, only the less efficient direct-drive ones. Supposedly the Queen Elizabeth class would have been 2+ knots faster if they had geared turbines and small tube boilers.

[pontiouspilot]

interesting.....I always wondered why the Germans didn't put diesels in their tanks (AFVs). Diesel is much easier and cheaper to produce and a hell of a lot less flammable.

[Dili]

No there wasn't patent lock by Germans in diesel engines. A bit of British Merchants(some relatively big like Warwick Castle 20000grt https://www.wrecksite.eu/wreck.aspx?17048 ).

Here is a pdf discussing the Liberty ship re-motorization post war - they were considered too slow - Check the advantages for diesel https://archive.org/details/USMALiberty ... 7/page/n71

Also i got this interesting tidbit from British Bank line,they were already building diesel but some were also with quadruple expansion :

The Oil Burning or Coal Burning steamships had interesting quadruple expansion engines and were built expressly for Weirs with interchangeable fuel burned in their boilers. Coal or oil was purchased when required in either format dependent upon price and availability, the ship's engineers being required to make the boiler burner alterations to suit. Generally, however, the engineers preferred the cleaner oil over the dirty and heavy work of coal.

https://www.shipsnostalgia.com/guides/B ... e_-_Part_2

[sstevens06]

Dili, very helpful as always - thank you!

[Dili]

ORIGINAL: pontiouspilot

interesting.....I always wondered why the Germans didn't put diesels in their tanks (AFVs). Diesel is much easier and cheaper to produce and a hell of a lot less flammable.

Might be they could not get the power output necessary from them with restriction in size and weight that were not so critical in ships. Italians had diesel tank engines but their tanks were very light. T-34 was on diesels too so that is a counter argument since it is a medium tank, maybe that just what the engineers in tank production were more familiar. inertia.


glad you liked sstevens06

[Ian R]

ORIGINAL: Zorch

Someone will probably correct me on this, but I thought the R class BBs used turbines from launch; it's just that they were coal-fired in most boilers.

I had a look at that in Conways. The "Revenge" class (as described in the Admiralty papers for the 1913 building programme) were designed as cheaper versions of the 'cutting edge' QEs.

The original design, when the first three keels were laid in 1913, and the 4th and 5th in 1914, was 'multi-fuel' with both coal and oil, and 4 shaft Parson's turbines, for 21.5kts.

Renee Greger in his book (page 87) says the lower speed, compared to the QEs, was acceptable because the ships were specifically designed for North Sea duty, and the German High Seas Fleet was limited to not more than 21kts anyway.

RN concerns about fuel oil supplies where alleviated when Sir Winston Churchill arranged for the strategic purchase of shares in the Anglo-Iranian oil company, and in January 1915 the design was altered (even though two had been launched) to pure oil firing, with a consequent increase from 31,000 to 40,000 SHP, and speed increased to 23 knots (not that they ever achieved that) - I.E. making them a more austere version of the "second generation" QE fast battleship. For example, they only had one rudder (plus a smaller hand operated rudder centreline ahead of it, which proved useless and was later removed).

This in one sense compares favourably with the QEs, whose turbines produced 56,000 SHP on a similar displacement, and also rated at 23kts. However, the power limitations, and other aspects of "accepting the lowest bidder" procurement, made them less amenable to later modernisation. Also, on trials with torpedo protection bulges added, the speed dropped by 0.5kts, albeit they became more stable gun platforms.

In August 1914 the 6th and 7th units were suspended and later re-ordered as the BCs Renown and Repulse, and the 8th unit (Resistance) was canned.

Only one of the five ships received an extensive rebuild in the 1930s - the Royal Oak, which was ironically sunk at anchor by a U-boat. The other four were retired to reserve during the war after performing useful convoy escort and bombardment duties.

Winston Churchill, writing after 1945, said the Admiralty spent most of the war keeping the R class BBs "as far away from the enemy as possible".

[BBfanboy]

ORIGINAL: Ian R

ORIGINAL: Zorch

Someone will probably correct me on this, but I thought the R class BBs used turbines from launch; it's just that they were coal-fired in most boilers.

I had a look at that in Conways. The "Revenge" class (as described in the Admiralty papers for the 1913 building programme) were designed as cheaper versions of the 'cutting edge' QEs.

The original design, when the first three keels were laid in 1913, and the 4th and 5th in 1914, was 'multi-fuel' with both coal and oil, and 4 shaft Parson's turbines, for 21.5kts.

Renee Greger in his book (page 87) says the lower speed, compared to the QEs, was acceptable because the ships were specifically designed for North Sea duty, and the German High Seas Fleet was limited to not more than 21kts anyway.

RN concerns about fuel oil supplies where alleviated when Sir Winston Churchill arranged for the strategic purchase of shares in the Anglo-Iranian oil company, and in January 1915 the design was altered (even though two had been launched) to pure oil firing, with a consequent increase from 31,000 to 40,000 SHP, and speed increased to 23 knots (not that they ever achieved that) - I.E. making them a more austere version of the "second generation" QE fast battleship. For example, they only had one rudder (plus a smaller hand operated rudder centreline ahead of it, which proved useless and was later removed).

This in one sense compares favourably with the QEs, whose turbines produced 56,000 SHP on a similar displacement, and also rated at 23kts. However, the power limitations, and other aspects of "accepting the lowest bidder" procurement, made them less amenable to later modernisation. Also, on trials with torpedo protection bulges added, the speed dropped by 0.5kts, albeit they became more stable gun platforms.

In August 1914 the 6th and 7th units were suspended and later re-ordered as the BCs Renown and Repulse, and the 8th unit (Resistance) was canned.

Only one of the five ships received an extensive rebuild in the 1930s - the Royal Oak, which was ironically sunk at anchor by a U-boat. The other four were retired to reserve during the war after performing useful convoy escort and bombardment duties.

Winston Churchill, writing after 1945, said the Admiralty spent most of the war keeping the R class BBs "as far away from the enemy as possible".

Thanks for the detailed info on their design history. I am puzzled by the statement about the sixth and seventh units becoming BCs Repulse and Renown (AKA Repair and Refit). The BCs had a much longer hull to accommodate their additional boilers/machinery for higher speed. Does that mean just the money for construction was diverted, or had the R class 6th and 7th keels already laid down?

[Jorge_Stanbury]

A bit off topic, but still talking about troopships

Big ships like SS Normandy, or some early US battleships or Lexington class carriers got turbo-electric drives instead of conventional turbines.
But then few ships during or after WW2 got it; curious to know what were the reasons to go back to reduction geared turbines

[fcooke]

I think the idea that for units 6 & 7 the funds were freed up for the BCs - not that hulls had been started and converted.

[Ian R]

ORIGINAL: BBfanboy

I am puzzled by the statement about the sixth and seventh units becoming BCs Repulse and Renown (AKA Repair and Refit). The BCs had a much longer hull to accommodate their additional boilers/machinery for higher speed. Does that mean just the money for construction was diverted, or had the R class 6th and 7th keels already laid down?

Yes & No.

Greger gives (oddly) a lay down date of 30-11-14 for Repulse as a BB, and a "?" for Renown; Conway's says construction as BBs had been suspended in August '14 but the material* that had been gathered was held at the yards pending a final decision. [*including gun mountings, turntables, and 15" rifles.]

Greger says the BCs had their keels laid 25 January 1915. He also comments that Repulse was transferred from Palmers to John Brown, as the former's slipway was too short for the BC design, which was about 50 metres longer.

The really astonishing figure is that the BCs were designed to develop 120,000** SHP (3 x the BB's), seeking a design speed of 32 kts. [**Greger's figure - Conway's says 112,000 SHP] Trial speeds were:

Repulse - 31.73kts @ 119,025 SHP
Renown - 32.56kts @ 126,000 SHP.

Service speed was however limited to 29.7kts @ 100,800 SHP.

Antony Preston in Conways (1906-21 volume) notes that within weeks of the BCs joining the fleet in late 1916, Sir John Jellicoe "suggested" they go back to the yard and be up-armoured. That resulted in an additional 500 tons of plate installed on each; that band-aid was followed by the addition of internal stiffening because they were too lightly built. But they were still inadequately protected.

Repulse was rebuilt 1918-21 and acquired the 9" belt originally installed on the Almirante Cochrane (rebuilding as the CV Eagle), among other improvements. Repulse was rebuilt again 1933-36, but not as drastically as Renown.

Renown was rebuilt 1923-26, also getting a 9" belt. Renown was reconstructed a second time 1936-39, and modernised to serve as a fast carrier escort. This included a new tower superstructure, landing of all existing secondaries and installation of 20 x DP 4.5" (10 x 2) etc.

I would not be surprised if "Refit" and "Repair" have generated some doctoral theses on how NOT to go about naval procurement. To damn them with faint praise, Mr Preston says:-

"They [referring to the Courageous and Glorious in original light BC form] were even bigger white elephants than the Renown and the Repulse, for which no proper role could be imagined"

[fcooke]

I've only scratched the surface of this but it fascinating. Some ships look bigger or smaller than their tonnage indicates, which drives home why sub captains often got the size of their targets wrong. Has anyone cross-referenced ones that should be in the game but are not?