Standard v full load

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paul.mercer
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Standard v full load

Post by paul.mercer » Wed Oct 03, 2018 9:51 am

Gentlemen,
Perhaps you could help with something that is puzzling me, standard load and full load.
I have always assumed that standard was 'as built' without fuel, ammo, stores etc and full would mean everything included. So when the Washington Treaty was signed for battleships to be 35000 tons, presumably this was as 'standard load'
I was looking up the 'R' class ships and it seems that their standard weight was around 29000 tons and 21 knots with full load being 33500 tons whereas the ships that they were meant to replace QE's,which were 27000 and 35500 tons respectively and 25 knots which seems strange that the RN built ships like the R''s that were slower and smaller than the ones they were supposed to replace! I realise that some of the QE's were heavily modernised but he difference 2000 tons seems quite a lot. looking at the design specs it appears that the 'R's'had slightly heavier armour so it seems a bit odd that it was the QE's that had their guns elevated and were the ones to be modernised.

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Dave Saxton
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Re: Standard v full load

Post by Dave Saxton » Wed Oct 03, 2018 4:17 pm

Standard Displacement is a creation of the treaties. The Rs and the QEs predate the treaties so that was not factor in their designs. The Rs were probably designed to get more ships for less money per ship than the QEs.

Standard displacement, according to the Treaties, was the ship fully stored and ammunitioned, but lacking fuel, lubricants, and boiler feed water. Such a standard was needed to make sure that treaty ships were more apples to apples, instead of apples to oranges.

For example, a warship designed to operate primarily in the Mediterranean, doesn't need much fuel. So more weight fraction can be committed to armour and firepower, or machinery. A warship designed to operate in the Pacific needs a lot of fuel fraction on the other hand, so if it was based on limiting full load displacement then a warship that must carry a lot of fuel would need to have less firepower, or armour, or speed.
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Re: Standard v full load

Post by dunmunro » Wed Oct 03, 2018 6:38 pm

Here's the exact wording that defines Standard Displacement:
The standard displacement of a ship is the displacement of the ship complete, fully manned, engined, and equipped ready for sea, including all armament and ammunition, equipment, outfit, provisions and fresh water for crew, miscellaneous stores and implements of every description that are intended to be carried in war, but without fuel or reserve feed water on board.
http://www.ibiblio.org/pha/pre-war/1922/nav_lim.html

paul.mercer
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Re: Standard v full load

Post by paul.mercer » Wed Oct 03, 2018 8:15 pm

Thanks for you replies, if standard displacement does not allow for fuel and there is a discrepancy of around 10000 tons, would that all be fuel or was there some rather crafty armour or armament additions?
Also I still not sure why the RN would build new ships that were inferior to the QE's not only in speed but other factors, was is because at the end of WW1 the RN had by far the biggest navy in the world and were too complacent about building bigger, faster ships because the thought they were unlikely to be challenged in the foreseeable future?
One more question, when speed trials were carried out and a ship achieved say 28 knots over a measured mile, would that have been under full load,
if it is not, then are all the maximum speeds quoted just theoretical, because any further weight of full tanks would surely slow them down a bit?

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Re: Standard v full load

Post by dunmunro » Wed Oct 03, 2018 9:35 pm

paul.mercer wrote:
Wed Oct 03, 2018 8:15 pm
Thanks for you replies, if standard displacement does not allow for fuel and there is a discrepancy of around 10000 tons, would that all be fuel or was there some rather crafty armour or armament additions?
Also I still not sure why the RN would build new ships that were inferior to the QE's not only in speed but other factors, was is because at the end of WW1 the RN had by far the biggest navy in the world and were too complacent about building bigger, faster ships because the thought they were unlikely to be challenged in the foreseeable future?
One more question, when speed trials were carried out and a ship achieved say 28 knots over a measured mile, would that have been under full load,
if it is not, then are all the maximum speeds quoted just theoretical, because any further weight of full tanks would surely slow them down a bit?
Typically standard displacement plus full fuel and other liquids = full load (sometime called "extra deep").

The R class actually had more armour (the 13in portion of the main belt was much larger than on the QE class) than the QE class. IIRC, they had less powerful engines because there was a fear that the RN might not have sufficient access to oil and that some battleships might have to revert to coal. In the event the R's retained oil as fuel but it was too late in the design stage to revert to more powerful engines.

In the RN acceptance trials were usually run at trials displacement which was full load minus about 1/3 fuel. This was to simulate combat conditions at the point of contact with the enemy, which was usually some distance from an RN base.

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Re: Standard v full load

Post by GiZi » Thu Oct 04, 2018 3:06 am

Since the discussion is being had;

I'd like to ask something regarding the definition.

The WNT defines standard displacement as;
The standard displacement of a ship is the displacement of the ship complete, fully manned, engined, and equipped ready for sea, including all armament and ammunition, equipment, outfit, provisions and fresh water for crew, miscellaneous stores and implements of every description that are intended to be carried in war, but without fuel or reserve feed water on board.

The word "ton" in the present Treaty, except in the expression "metric tons", shall be understood to mean the ton of 2240 pounds (1016 kilos).

Vessels now completed shall retain their present ratings of displacement tonnage in accordance with their national system of measurement. However, a Power expressing displacement in metric tons shall be considered for the application of the present Treaty as owning only the equivalent displacement in tons of 2240 pounds.

A vessel completed hereafter shall be rated at its displacement tonnage when in the standard condition defined herein.
Emphasis mine.

Yet, the definition does not seem to match up with that used elsewhere.

For example, the listed breakdown of the displacement of the cruiser Algérie, according to John Jordan and Jean Moulin, is as follows (in metric tons);

Hull: 3800 tons
Protection (hull): 1720 tons
Protection (armament): 315 tons
Armament: 1415 tons
Propulsion: 1335 tons
Torpedoes/Aircraft: 111 tons
Fittings/Provisions: 1427 tons
Misc.: 37 tons
Washington Displacement: 10,160 tons (10,000 long tons)

Oil Fuel & Reserve Feed Water: 750 tons
Misc.: 40 tons
Normal Displacement: 10,950 tons

Oil Fuel + Combustibles + Ammunition + Misc.: 2727 tons
Full Load Displacement: 13,677 tons

This conflicts with the WNT definition, as the French 'Washington Displacement' meant for treaty compliance is simply the ship as built with nothing loaded aboard it, given there is much more than fuel and RFW being loaded aboard.


Perhaps an even better example is the le Fantasque-class, since the breakdown of her tonnage is more detailed, from the same authors;

Hull: 957.77 tons
Protection: 1.31 tons
Guns: 218.24 tons
Torpedoes: 60.66 tons
Mines/Depth Charges: 12.5 tons
Machinery: 1016.38 tons
Weight related to displacement: 191.18 tons
Weight related to machinery: 95.56 tons
Special fittings: 34.73 tons
Margin: 20.85 tons
Washington Standard Displacement: 2609 tons

Oil fuel: 120 tons
Reserve feed water: 43 tons
Consumables: 10 tons
Ammunition: 58 tons
Normal Displacement: 2840 tons

Oil fuel (for 360 tons): 240 tons
Reserve feed water: 85 tons
Ammunition: 13 tons
Various: 2 tons
Load Displacement: 3180 tons

Oil fuel (for 580 tons): 220 tons
Ammunition (wartime): 17 tons
Deep load displacement: 3417 tons

They also note;
Under the Washington Treaty, neither the fuel oil nor the reserve feed water were counted in ‘standard’ displacement, but although Washington standard displacements were calculated (retrospectively) for these ships, these considerations had no impact on French destroyer design during the period 1922-1930.
This does not make any sense, however, as surely the true 'Washington displacement' of a le Fantasque, by treaty definition, would be in the order of 2709 tons, as that is the displacement of the ship with all aboard save for fuel oil and reserve feed water.

I assume I'm missing something extremely obvious here, but for those with a greater understanding, why exactly is there such a disparity in definition of 'Washington standard' displacement?

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Re: Standard v full load

Post by dunmunro » Thu Oct 04, 2018 4:21 am

There was a gentlemans agreement amongst the treaty powers that allowed for small increases in displacement beyond the limit because it was hard to accurately estimate many of the construction and weapon weights.

There was also an unwritten allowance made for ships to be able to carry 'overloads' of ammunition by ~20% or so during wartime, but I'd need to see if any ammunition was included in the French calculations

paul.mercer
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Re: Standard v full load

Post by paul.mercer » Thu Oct 04, 2018 9:15 am

dunmunro wrote:
Thu Oct 04, 2018 4:21 am
There was a gentlemans agreement amongst the treaty powers that allowed for small increases in displacement beyond the limit because it was hard to accurately estimate many of the construction and weapon weights.

There was also an unwritten allowance made for ships to be able to carry 'overloads' of ammunition by ~20% or so during wartime, but I'd need to see if any ammunition was included in the French calculations
Gentlemen,
Again, many thanks for your expertise and your replies - it appears that as the war progressed there were not many 'gentlemen' left among the countries that were fighting!

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