Construction of Warships - Drydocks

GJPBoston · Nov 21, 2018

Takao

Takao said: ↑

For the US. graving docks were much less of a factor than slipways. Simply put, graving docks were needed, not just for routine maintenance, but also to repair a steady stream of damaged vessels returning from the Atlantic and Pacific. More than likely, this would go for most other major naval powers.

Bottlenecks could be many...Maintaining a steady supply of steel and armor, propulsion always needed a long lead time, the yards needed to maintain enough workers to work 24/7(the yards needed not just skilled workers but also "white collar" workers such as managers, engineers, naval architects, supervisors, & foremen), prefabrication helped to speed the construction process(however, it could also make things more difficult when prefabs didn't match up - The German Type XXIs were notorious for this). Then there is the fitting out process after launch - IIRC, the US lacked a steady supply of 40mm Bofors and 5-inch/38s early in the war, and this lead to hold ups. The Japanese also ran into similar problems - like having older guns with a newer fire control systems or newer guns with old fire control systems. It also took the Japanese a few years to replace their older heavy AA guns with more modern ones.

AFAIK, all ships were built on the slipways. The only variance to this, that I know of was Slipway D at Manitowac Shipyards which used a side-lauch system, and way D was large enough to accommodate one submarine that was being readied for launch and one that was just beggining construction. However, there were only two occasions where this was done.

That being said...Prefabrication of parts, but not necessarily sections, was relied on to speed construction of ships of all types, and shipyards had separate storage areas for these parts.

For the most part, the prefabricated sections were built at the shipyard, and would then be moved to the slipway and welded in place on the ship. Prefabricated work amounted to about 61% of a Liberty ship. The record-holder was the Liberty Ship "Robert E. Perry" which, on November 12, 1942, had gone from keel-laying to launching in 4 days 15 hours and 26 minutes. Further, Liberty ships were launched essentially complete, whereas, warships would then be moved to a "fitting out" dock/pier and take some months to complete. So, in essence, warships did not tie up slipways for their whole period of "complete" construction either.

That being said, the "Robert E. Perry" was an outlier, and the shipbuilding process was an evolutionary one, with the average time of completion going from a high of 239.8 days in January, 1942 to a low of 61.8 days in February thru June, 1945.
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Takao, Very helpful answer, thank you. I was off course, and you have steered me back in the right direction.

I appreciate everyone's answers. In case of interest to anyone, I had been looking at French pre-WW2 graving docks, and here is what I have found so far. Should be fairly complete for French navy operated graving docks, but probably very incomplete for commercial:

Port Dock, Type, Dimensions, Military/Commercial
Brest

Laninon Dock 8, Graving Dock, 250x36 m, Military Dock
Laninon Dock 9, Graving Dock 250x36 m, Military Dock
Pontaniou No. 2, Graving Dock 178x27 m, Military Dock
Pontaniou No. 3, Graving Dock 178x33 m, Military Dock
Bassin Redoub Commerce No. 1, 225 m, Commercial Dock

Cherbourg

Forme du Homet, Graving Dock 249x36 m, Military Dock

St. Nazaire

Louis Joubert Lock, Graving Dock, 350 m, Commercial Dock
Bassin 1, 241 m
Bassin 2, 200 m

Toulon

Missiessy Basin No. 1, Graving Dock, 202x30 m, Military Dock
Missiessy Basin No .2, Graving Dock, 202x30 m, Military Dock
Missiessy Basin No. 3, Graving Dock, 179x30 m, Military Dock
Vauban Grands Bassins 1-2, Graving Dock, 250 - 408 x40m, Military Dock
Vauban Grands Bassins 3-4, Graving Dock, 250 - 408 x40 m, Military Dock

Le Havre

No. 7 Dock, Graving Dock, 319x38 m, Commercial Dock

Bizerte

Dock No. 2, Graving Dock, 254x40 m, Military Dock
Graving Dock, 203X30m, Military Dock
Graving Dock, 203x30m, Military Dock
Graving Dock, 92x15m, Military Dock

Oran

Graving Dock, ?, Commercial
Graving Dock, ?, Commercial

Alger

Graving Dock, 138x26m, Commercial
Graving Dock, 80x22m, Commercial

Dakar

Graving Dock, 198m, ?
Floating Drydock, ?

Casablanca

Floating Drydock, 150x25m, ?
Floating Drydock, 150x25m, ?
Floating Drydock, 80x22m, ?
Floating Drydock, 80x22m, ?

Fort de France

Graving Dock, 190x25m, ?

Here is what I have found for facilities that can build large capital ships:

Port, Dock, Dimensions

Brest

Salou No. 4, Building Dock, 200x40 m

St. Nazaire

Forme Caquot, Building Dock, 325x46 m
Penhoet No. 1 Slipway, Slipway, 315x36 m

lwd · Nov 21, 2018

There were a thread or two over on the Axis history forum that went into details about the slips available to some of the powers prior to and during the war. Not directly related to the above but you might find them of interest.

Takao · Nov 21, 2018

Link to the old 2009 AHF thread, Mescal's response on French dry docks:
https://forum.axishistory.com/viewtopic.php?p=1396682#p1396682

Takao · Nov 21, 2018

lwd said: ↑

There were a thread or two over on the Axis history forum that went into details about the slips available to some of the powers prior to and during the war. Not directly related to the above but you might find them of interest.
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So long ago, I'd forgotten about it.

Carronade · Nov 21, 2018

As @GJPBoston noted, the drydocks at Brest were 250m long, which is probably why the Richelieu class battleships were 248m.

Bismarck and Tirpitz were 251m, one meter too long to be docked at Brest unless they squeezed them in on an angle as in the photo @Takao provided. This is what made the Normandie dock at St. Nazaire so important.

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Construction of Warships - Drydocks

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