Battlecruiser: Design studies for the Royal Netherlands Navy 1939-40 (Warship International No. 4

Battlecruiser

Design studies for the Royal Netherlands Navy 1939-40

By Lt. Jurrien S. Noot, Royal Netherlands Navy

Author.s note:
The information presented in the article is not intended as a full design history in narrative form of the battlecruisers once proposed to be constructed for the Royal Netherlands Navy. This would not be possible anyway because only fragmentary records appear to remain. Rather, I have tried to present the basic information found in the files of the Naval Historical Division of the Naval Staff in The Hague in an orderly form to give some understanding of the characteristics of the various designs that evolved, and to publish all the more pertinent drawings that were produced.

Due to the fact that my research had to be limited to the files of the Naval Historical Division, it is quite possible that the article does not give a complete presentation of the facts. Any person who is in possession of additional information from original records is invited to comment. I am thinking of those who may have access to the German World War II files that may contain some original data on these ships, since at the outbreak of war in May 1940, all Dutch records seem to have been requisitioned by the Germans. There is no way of knowing at present if any material was ever returned.

Editor.s note
The Dutch battlecruiser designs of 1939-40 were made known in detail first by the late R.F. Scheltema de Heere in his article .Slagkruisers voor Nederlands-Indië 1939. in Marineblad Vol. 76 No.2 (Maart 1966), pp. 127-147. Lt. Noot.s article provides a fuller documentary record of the design work and makes the story available to English language readers for the first time. Dutch naval programs of the late 1930s are also addressed in detail in L.L. von Munching.s .H.Nl.M.S. De Zeven Provincien C-802. in Warship International No.4, 1976, pp. 251-269.

Editor.s note
We thank William A. Becker for his many hours spent in tracing the many drawings used in this article.

Introduction
In 1938 A COMMITTEE consisting of high ranking naval officers was appointed to investigate various possibilities of strengthening the naval forces of the Netherlands. The main conclusion of this investigation was that the Royal Netherlands Navy would have to be strengthened in such a way that any aggressor would be forced to use such a large part of his military potential that there would be an unacceptable weakening of his capabilities in other theatres.

Within the context of this investigation, Mr. J.J.C. van Dijk, the Minister of Defence, instructed the Navy Department on 18 February 1939 to work out a plan for the construction of a heavy naval unit. This instruction was the result of a note from the Chief of Naval Staff (a copy of which has not been found) in which the construction of such a vessel had been proposed, along with the construction of a third light cruiser. However, the Minister of Defence would not allow this third light cruiser to be incorporated into the program, and stated that any proposals made would have to be within the context of the naval program currently planned. It was to be considered what possible savings could be made on the basis of either a reduction of the calibre of the main armament or a reduction in the number of guns carried. Cost estimates were to be provided for the construction of 2 or 3 battlecruisers, including an analysis of the personnel consequences, and it was to be investigated if the ships could be constructed in Dutch shipyards.

Staff requirements
The Navy Staff requirements for the proposed battlecruisers had been defined on 17 February 1939 as follows:

Speed:	Maximum speed in tropical waters to be 32 kts., to be sustained at least 12 hours. Acceleration from 20 kts., cruising speed to 30 kts. to possible within 15 minutes.
Propulsion:	Not to be fitted with peacetime propellers, which would necessitate changing propellers during times of tension. Well thought out engineroom subdivision, to limit possible loss of speed in case of being hit in this area.
Radius:	To be 4500 NM at 20 kts., to compare with the 1938 Light Cruiser Design
Heavy Artillery:	Three 28cm triple turrets, 120 rounds per gun. Turrets to be fitted for independent firing.
Medium Artillery:	Serving as anti-aircraft and anti-torpedoboat battery. Four twin 12cm mounts (as in gunboats but need not be stabilized), 120 rounds per gun, 100 starshells. All 12cm guns to be capable of independent firing.
Light Artillery:	One group of three twin 40mm machineguns to be fitted forward with centralized fire control; one group of four twin 40mm mounts to be fitted aft with centralized fire control. 1000 rounds per barrel to be carried.
Torpedoes:	No torpedo armament.
Aircraft:	Two fighter aircraft and two reconnaissance aircraft. If possible, two catapults to be fitted (one to port and one to starboard). Hangar for at least two aircraft
Armor:	(a) Excellent anti-torpedo and anti-mine protection.
	(b) Armor in general to be able to withstand 28cm shell hits and 300kg aircraft bombs.
	(c) Armor scheme to be as follows:
	Main belt to extend from aft to forward turret	250 mm
	Remaining waterline belt	80 mm
	Main armored belt	125 mm
	Splinterdeck on top of armored deck	30 mm
	Control tower . sides	300 mm
	Control tower . roof	150 mm
	28cm turrets . barbette	250 mm
	28cm turrets . front	300 mm
	28cm turrets . roof	150 mm
	28cm turrets . sides	100 mm
	12cm mounts . barbette	80 mm
	12cm mounts . front	80 mm
	12cm mounts . roof	125 mm
	12cm mounts . to be protected against the effect of 200kg aircraft bombs and 14cm shell hits.
	(d) Steering gear to be well protected.
	(e) Machine guns to be mounted on armored decks and protected with 40mm splinter armor
	(f) Anti-torpedo bulkheads extending to double bottom and to be able to absorb 53cm torpedo hits.
Draft:	Deep load draft not exceeding 9 meters, preferably less.
Logistics:	Supplies to last for six weeks. 60 tons fuel for Dornier aircraft. 25 tons fuel for MTBs. 100 tons aircraft fuel.
Complement:	Accommodations for 50 officers, 100 non-commissioned officers, 900 ratings.
General:	It was to be investigated what possible financial savings could be achieved if the main battery was reduced to six guns.

The basic design requirements were formulated again on 21 February 1939 in a letter by the Chief of Naval Staff (copy not found), and on 22 February 1939 orally passed to the Naval Construction Department. It was estimated that the length of the ship would be about 240 meters, the beam about 29 meters and the draft about 7.50 meters, and that it need 180.000 SHP divided over 4 shafts. The Construction Department worked out a preliminary design on the basis of these requirements, which was completed on 11 July 1939 (see Table 1 for the characteristics of the design).

Table 1 - Design characteristics: 1939 Preliminary Design dated 11 July 1939
Dimensions
Length on DWL	230.00m
Beam-max. (over armor)	29.65m
Beam-max. (over frames)	29.00m
Draft (trial displacement)	7.45m
Molded depth (centerline)	13.80m
Molded depth (sides)	13.40m
Displacement
Washington	26000 t
Trial	26998.5T
Normal load	27916.0T
Machinery
Shaft horsepower	160000
Drive	Steam turbines
Boilers	4 x 2
Propellers	4
Max. speed	33 kts.
Radius	4500 NM at 20 kts.
Armament
Main armament	9 x 28cm in triple turrets (120 rounds per gun)
Secondary armament	8 x 12cm in twin turrets (200 rounds per gun)
Anti-aircraft armament	14 x 40mm in twin mounts (1000 rounds per gun)
Various armaments	2 catapults 2 aircraft.
Armor & protection
Vertical side belt	250mm tapering upwards to 150mm
side belt	250mm tapering upwards to 150mm and 100mm
side aft	100mm
side forward	100mm
longitudinal bulkheads	two 30mm each side
main transverse bulkheads	not indicated
Horizontal
main armored deck	125mm
upper deck	15mm
Artillery - 28cm turret
front	300mm
roof	130mm
sides	100mm
barbette	250mm
Underwater
double bottom depth	1.00m
depth of side protective system	7.00m
depth of main side belt	6.00m (2.45m below DWL). System consisting of two longitudinal anti-torpedo bulkheads on each side.
Various	2 paravanes, 3 smokemakers, 100m³ gasoline.
Coefficients of form
Block coefficient	0.5193
Midship section coefficient	0.9617
Prismatic coefficient	0.5400
Waterline coefficient	0.6700
Note: Exact particulars of this preliminary design are not clear. According to one description this would have been a two-funneled ship, but the surviving drawing of 11 July 1939 shows a one funneled ship.

	Battlecruiser Preliminary design 1939 (I) (11 July 1939) This drawing gives an overview of armament lay-out and the ships' general profile. (Click on the drawing on the left. The link will open a new window)
	Battlecruiser Preliminary design 1939 (II) (11 July 1939) This drawing gives an overview of the ships' subdivision (Click on the drawing on the left. The link will open a new window)
	Battlecruiser Preliminary design 1939 (III) (11 July 1939) This drawing gives a cross-section overview of armor distribution. (Click on the drawing on the left. The link will open a new window)

However, it is apparent that the Dutch naval constructors had little knowledge of the technical developments that had taken place in capital ship design subsequent to the First World War, particularly with regard to protection. Although the preliminary design featured a good horizontal protection (consisting of a 125 mm main armored deck with a 15 mm deck on top), the general arrangement and the distribution of armor resulted in a capital ship design dating 20 to 25 years back. In fact, it appears that the only useful reference material available consisted of open source literature and Jane.s Fighting Ships. It was clear that technical assistance from abroad was imperative in order to produce a suitable up-to-date design.

Although there was some hope that the French would release drawings of their Dunkerque Class battlecruisers, the Dutch authorities felt that it would be best to concentrate efforts to obtain foreign assistance to Germany, at least for the time being. So it happened that the first informal discussions with German authorities regarding the battlecruiser project occurred on 24 and 25 April 1939 in Berlin. The Dutch delegation stated that they were interested in the release of a complete German design of a Gneisenau type vessel, in return for which the necessary equipment would be ordered from Germany. It was also proposed that Dr. Techel of the .Ingenieurskantoor voor Scheepsbouw. (I.v.S.) would act as a trait d.union between the Dutch and German technicians. Although the Germans appeared to be genuinely interested in the project, they wanted guarantees that orders in Germany would actually take place if construction was to proceed, and that Germany would receive financial compensation in case the ships were not built. However, the release of the plans of the Gneisenau would be out of the question. The initial German reluctance can be attributed in part to the fact that so far the project was just that, while during the summer of 1939, the Dutch Cabinet was not convened so no political decisions of great magnitude could be taken.

In the meantime, a contact had been established with the German firm Ferrostaal A.G. Essen, and on 15 May 1939, a detailed listing of equipment to be ordered in Germany was submitted as follows:

Equipment	Required delivery date
37,500 tons of armor	June 1940 through January 1944 (the bulk to be delivered before January 1943)
18,000 tons of construction material	June 1940 through June 1943 (the bulk to be delivered before January 1942)
nine 28cm triple turrets and twelve 12cm twin mounts	Spring 1943 through late 1943
28cm and 12cm ammunition	Late 1943 through late 1944
6 catapults	July 1943 through late 1944
Propeller shafts	Late 1941 through late 1943
Various equipment for propulsion plant	1940 through 1942
15,000 tons of steel to be used for the construction of a floating dry dock	During 1942

During talks held in Bremen (13 July 1939) and in Berlin (31 July 1939), the Germans promised to release a design study that would incorporate their ideas on battlecruiser construction. This design study was submitted to the Royal Netherlands Navy on 21 August 1939, and showed various possible schemes of protection. Its basic characteristics are listed in Table 2.

Table 2 - Design characteristics: German Sketch Design 21 July 1939 .Holland-Schlachtschiff.
Dimensions
Length on DWL	227m
Beam	30m
Draft on DWL	8m
Moulded depth	14m
Displacement (metric tons)
Hull (S I-IV)	8000
Armor & Protection (P)	9900
Main engines (M I)	3100
Aux. engines (M II)	1000
Aircraft	80
Gunnery armament	4100
Equipment	650
Water	200
Reserve	470
Type displacement	27500
Feed water & fuel oil	2000
Legend displacement (DWL)	29500
Type displacement	27500
Max fuel oil	4600
Lubricating oil, etc.	200
Feed water	160
Reserve drinking & washing water	340
Full load displacement	33000
Machinery
SHP	ca. 172.000
Main engines	4 high pressure turbine sets
Radius	ca. 5500 NM at 20 kts.
Speed (legend displacement)	ca. 33 kts.
Armament
Armament	9 x 28 cm in triple turrets (150 rounds per gun) 8 x 12 cm in twin turrets (200 rounds per gun) 16 x 40 mm (ammo not indicated)
Armor and protection
Vertical side belt	225mm
Side aft	60mm
Side forward	30mm
Citadel	60mm
Longitudinal side bulkheads	30mm and 20mm
Citadel longitudinal bulkhead	15mm
Horizontal main deck	100 and 125mm
upper deck	30 and 20 mm
Artillery 28cm barbette	170mm and 225mm

	German profile drawing (21 July 1939) (Click on the drawing on the left. The link will open a new window)
	Various cross-section drawings of the German 1939 design (Click on the drawing on the left. The link will open a new window)
	Battleship design - general outlin (Berlin 21 July 1939) (Click on the drawing on the left. The link will open a new window)

The German Admiral Bartenbach, who had been appointed as liaison between the Royal Netherlands and German Navies, stated on 4 October 1939 that although the delivery dates of the equipment to be ordered in Germany could not be guaranteed, they would not be interfered with by orders from the German Navy from the same firms and pressure would be put on them to meet the required dates. On 10 November 1939, Ferrostaal AG Essen was formally appointed to act on behalf of the Royal Netherlands Navy for all technical assistance and all equipment to be obtained from Germany. This arrangement did not include the Krupp armaments firm; all these contact would be dealt with directly between the Royal Netherlands Navy and Krupp.

Propulsion plant
The Royal Netherlands Navy formulated by late August 1939 the design requirements for the propulsion plant as follows:

Propulsion power: 180.000 SHP

Eight boiler rooms, the boilers operating at 44 kg/cm² and 400^o C.

Four sets of geared turbines.

From aft to forward the basic distribution was to be as follows (compartments separated by a central longitudinal bulkhead)
          2 sets of geared turbines
          4 boiler rooms
          2 sets of geared turbines
          4 boiler rooms

By early October 1939, the requirements had been refined somewhat and included a fully independent set of turbines (consisting of turbines for full speed, economical speed and reverse each) for each of the four shafts. Output per shaft was to be 45,000 SHP, providing 34 kts. speed at about 270 shaft RPM with a propeller diameter of about 4.75 meters. Boiler working pressure would be 40-42 kg/cm² with at least 35-40 kg/cm² at the turbines; boiler temperature remained at 400^o C and coolant water temperature was to be 30^o C.

Based on these requirements both the Royal Netherlands Navy/NEVESBU and Krupp Germaniawerft (turbines) and Deschimag (boilers) started work on a series of preliminary designs for the propulsion plant.

	Layout of Machinery Spaces of German 1939 design (reflecting Dutch requirements) Click on the drawing on the left. The link will open a new window
	Cross-section of the German 1939 design (I) Click on the drawing on the left. The link will open a new window
	Cross-section of the German 1939 design (II) Click on the drawing on the left. The link will open a new window

However, from the beginning it was clear that in principle it was intended to construct the plant in the Netherlands. The results of the various German proposals were incorporated in various design studies drawn up by I.v.S., while the Dutch were incorporated in the Project 1047 design series (see below).

The first results of the German design studies were submitted in early December 1939, and a variety of proposals were considered . none of them being acceptable. By early February 1940 the proposed plants compared as follows:

Project	Boiler	Output	Area
323 Dutch design	Yarrow boilers/Parsons turbines operating at 44 kg/cm² / 400^o C	180,000 SHP	1209m²
323 IvS design	Deschimag boilers/GW turbines operating at 44 kg/cm² / 400^o C	180,000 SHP	910m²

From this table it is apparent that the Germans had designed a much more compact plant than the Dutch, but one of the main problems was that the Dutch feared that the German plant would be located in too restricted an area and might not operate flawlessly. A major problem was that no more than about 72.80 meters of ship.s length could be made available which led to an impasse, since the I.v.S.-design needed 74 meters and the Dutch 78 meters.

By early March 1940 the requirements for the propulsion plant were reconsidered, and the question was raised if 160.000 SHP would be sufficient. By mid-April 1940 the requirements were listed as follows:

(1) North sea conditions ca. 34 kts.	4 x 45.000 SHP specific steam output 3.50 kg/SHPh at 92% vacuum	630.000 kg/h
(2) Tropic Water conditions ca. 33 kts.	4 x 40.000 SHP specific steam output 3.60 kg/SHPh at 85% vacuum	575.000 kg/h
(3) Necessary steam production per hour for other purposes would be approximately 153.000 kg/h so that the boilers were to be designed for a specific steam output of 800.000 kg/h taking 2,2% reserve.
(4) The boilers would operate at 37 kg/cm² and 380^o C.

This reduction in the required power took into consideration that theoretically a plant designed at 180.000 SHP in tropical waters would in North Sea conditions actually produce ca. 200.000 SHP, driving the ship at 34.8 kts.

Dutch estimates by early March 1940 provided for a total length of the propulsion plant complex as follows:

Boiler room (2 boilers)	10.50 meters
Boiler room (2 boilers)	10.50 meters
Turbine room	15.75 meters
Boiler room (2 boilers)	10.50 meters
Boiler room (2 boilers)	10.50 meters
Turbine room	15.75 meters
Total	73.50 meters

The central longitudinal bulkhead originally required had by this time been abandoned as a result of the visit to Italy (see below).

On 20 April 1940 (drawing X 1c) the requirements had again been changed so far as required length was concerned.

Centrale
No.1 Boiler room (2 boilers)	8.25 meters
No.1 Boiler room (2 boilers)	8.25 meters
No.1 Engine room	15.00 meters
Centrale	7.50 meters
No.3 Boiler room (2 boilers)	8.25 meters
No.4 Boiler room (2 boilers)	8.25 meters
No.2 Engine room	15.00 meters
Total	79.50 meters*
* Note webmaster: calculation adds up to 70,50. There is a discrepancy of 9 meters

Armament
The basic requirements for the armament were discussed by representatives of the Royal Netherlands Navy and Krupp at Essen on 31 July 1939. The required characteristics at that time were as follows:

(1) 28,3cm triple turret
Projectile weight	ca. 300 kg
Initial velocity (v)	850-900 m/s
Recoil	ca. 250t per barrel
Max. elevation	45^o
Max. depression	10^o
Elevation	hydraulic
Training	electric
Ammo storage	separate loading arrangements for projectiles (lower) and powder bags (upper).
Electrical power needed	500 kW max. 260 kW average.
Armor	front: 300mm forward incline: 200mm roof: 150mm sides: 100mm back: P.M. barbette: 250 mm
Turret weight	ca. 800 t
(2) 12 cm twin AA
Max. elevation	80^o
Max. depression	10^o
Armor	front: ca. 80 mm roof: ca. 150 mm sides: ca. 50 mm back: P.M.

Fire control arrangements were discussed with the Dutch firm NV Hazemeyer Signaal Apparatenfabriek on 6 November 1939, and it appears that the following provisions were to be made.

(1) 28cm battery
(a)	one main fire control position forward (director control tower).
(b)	one reserve fire control position aft (director control tower).
(c)	one fire control position each in the superimposed forward turret and in the aft turret.
(d)	Main and reserve fire control positions were to be fully identical with a 9 meter optical base with target and laying centers co-located in a turntable platform protected by an armored cupola; both would have an independent computing center.
(2) 12cm battery
	Two fire control positions with a 3 meter optical base with target information and gun laying enters combined in a platform protected by an armored cupola.
(3) 40mm battery
	To be controlled autonomously from the gun positions.

Estimated unit cost
According to the preliminary cost estimates (undated) unit cost was assessed to be as follows (prices in DFL):

(1) Shipbuilding
Hull	975.000
Armor	15.625.000
160.000 SHP propulsion plant	9.600.000
Fittings (including catapult)	6.396.750
Trials & Insurance	960.000
Wages	3.400.000
Design & Drawings	1.500.000
Storage	3.740.000
Shipbuilding cost (w/o profit)	42.196.750
6% profit	2.531.805
Total shipbuilding cost	44,728,555
(2) Armament
3 28cm triple turrets	10.500.000
28cm ammo (1080 rounds)	1.350.000
28cm fire control	750.000
Optical rangefinders	300.000
4 12cm twin turrets	2.000.000
12cm ammo (1600 rounds)	200.000
starshells (100)	35.000
12cm fire control	1.400.000
Optical rangefinders	120.000
7 40mm twin mounts	450.000
Fire control	400.000
Optical equipment	80.000
40mm ammo (14000 rounds)	300.000
20 12.7mm twin mounts	340.000
12.7mm ammo (30.000 rounds)	50.000
Reserve ammo (100%)	1.935.000
2 additional 12cm twin turrets (including fire control and optics)	1.160.000
Total Armament cost	21.370.000
(3) Various equipment
Supplied by the Navy	3.114.000
Individual unit cost	69,212,555

This cost estimate was of course preliminary and in the Naval Plan 1940-45 the total cost for three vessels was judged to be DFL 213,000,000. Payment was to be spread out as follows:

Year	DFL
1940	30.600.000
1941	46.640.000
1942	48.635.000
1943	43.015.000
1944	27.310.000
1945	16.800.000
Note: Foreigh currency conversion rates during 1939 were as follows (approx.): 1 pound equalled DFL 8.75 (after 1 July 1939 DFL 7.50) 1 dollar equalled DFL 1.85 (Information supplied by Amsterdam Rotterdam Bank, 1978)

Detailed design work
The Construction Department (in collaboration with NEVESBU and the I.v.S.) started on detailed design work, based on the technical information obtained from German sources. The NEVESBU design series number was Project 1047, while I.v.S. called it Project 323. Project 1047 designs were fitted with Werkspoor/Yarrow propulsion plant while the I.v.S. Project 323 designs had the Deschimag/Germaniawerft propulsion plant. Detailed specifications of the various designs produced are listed under their separate headings.

I.v.S. Design activities
The I.v.S. independently started on design work for the battlecruisers based on information supplied by German firms and authorities, and taking into account the requirements formulated by the Royal Netherlands Navy. The first detailed design specifications, given in Table 3, were submitted for discussion with the Royal Netherlands Navy during mid-Noember 1939. These specifications are assumed to embody weight calculations from German sources but no specific record indicating this has been found.

Table 3 - I.v.S. Project 323 November 1939
Hull dimensions
Length at loaded waterline	238.40 m
Beam at loaded waterline	29.00 m
Draft at loaded waterline	8.40 m
Moulded depth	14.00 m
Displacement w/o attachments (loaded)	31911.00 m³
Displacement with attachments (loaded)	32390.00 m³
Displacement w/o attachments (loaded)	32709.00 T
Displacement with attachments (loaded)	33200.00 T
Midship section area	231.50 m²
Midship section coefficient	0.95
Block coefficient	0.55
Prismatic coefficient	0.58
Wetted surface w/o attachments	7390.0 m²
Weight distribution (metric tons)
I. Hull	8931
II. Armor (excluding revolving armor)	11122
III. Auxiliary equipment	948
IV. Main propulsion equipment	2880
V. Electrical	524
VI. Armament	2992
VII. Nautical equipment	70
VIII. Variable load	5093
IX. Margin (2%)	640
Normal load displacement	33.200
Washington displacement	29.815
Armor and protection
Main side belt	250mm (5 meter deep), tapering to 60mm forward and aft.
Longitudinal bulkheads	40mm
Citadel main transverse bulkheads	225mm forward and aft
Citadel secondary transverse bulkheads	40mm below 40mm armored deck
Main armored deck	150mm
Splinter deck	40mm (citadel area below main armored deck)
28cm barbettes	250 mm above main armored deck and 80 mm between main armored deck and splinter deck.
12cm barbettes	100 mm
Funnel and uptakes	(395 tons)
Control positions	(350 tons)
Armament
Armament	9 x 28cm/50 in triple turrets (total supply 1350 rounds) 12 x 12cm/53 in twin turrets (total supply 2400 rounds) 16 x 40mm in twin mounts (total supply 16000 rounds) 16 x 13mm in twin mounts (total supply not indicated) Catapult and 3 aircraft 100 depth charges
Machinery
SHP	180.000 (4 x 45.000)
Speed	34 kts (at 33,200 T displacement)
Fuel	2700 tons
Notes: Unfortunately, no drawings have been found that relate to these proposals made during November 1939. These specifications provide the only detail on record of the calibre length of the 28cm and 12cm guns planned for the Dutch battlecruisers, and in doing so indicate that the 28cm guns planned for the Dutch ships were not the same as mounted in the German Gneisenau Class.

The I.v.S. subsequently started on detailed hull design work, in which the last body plan produced dated 11 March 1940 showed the following characteristics.

Table 4 - I.v.S. Project 323 Body Plan 11 March 1940
Length between perpendiculars	235.00m
Beam at DWL (outside armor)	29.20m
Draft	7.90m
Displacement w/o attachments	29.340 m³
Wetted surface w/o attachments	7080 m³
Midship section area	217.70 m²
Block coefficient	0.541
Midship section coefficient	0.944
Prismatic coefficient	0.573

	IVS General Plan (18 March 1940) - Drawing H-79 of Project 323 (I) Click on the drawing on the left. The link will open a new window
	IVS General Plan (18 March 1940) - Drawing H-79 of Project 323 (II) Click on the drawing on the left. The link will open a new window
	IVS General Plan (18 March 1940) - Drawing H-79 of Project 323 (III) Click on the drawing on the left. The link will open a new window

Design Work of the Royal Netherlands Navy
Although in autumn 1939 design work was well underway, and cooperation with Germany seemed reasonably assured, some reluctance on their part was still in evidence. Accordingly, Admiral Vos (Chief of the Materiel Department of the Navy) recommended strongly in a letter on 6 December 1939 to the new Navy Minister that the plans for the construction of the battlecruisers be brought before Parliament before Christmas 1939. However, the Navy Minister had not yet made up his mind as to exactly what type of vessel needed to be constructed. He apparently favored a 16.000 ton ship of the armored cruiser type. During December 1939, the Naval Construction Department considered the possibilities of such a ship and came to the comparison presented in Table 5.

Table 5 - 16,000 Ton Project Armament & Protection Comparison
Displacement	16.000 tons Washington
Speed:	33 kts. in tropical waters.
Armament	Protection
Armament	Belt	Deck	Turret	Torpedo bulkhead
Three triple 28cm	100 mm	40 and 50	100	25
Three twin 28cm	120	50 and 60	120	30
Three triple 24cm	120	60	120	30
Three twin 24cm	140	65	150	30

It was noted that if the armor protection proposed for the 27.000 ton project were to be worked into a 16.000 design, no armament could be fitted. Also, it was considered that the plans for the former could be completed in 5 to 5,5 months, while if the Navy had to revert to a 16.000 ton design, a delay of 6 months was expected. A memorandum was drawn up on 11 December 1939 in which it was stated that on a 16.000 ton displacement, a design could be prepared with characteristics shown in Table 6.

Table 6 - 16.000 Ton Armored Cruiser
Displacement	16,000 tons Washington
Dimensions	ca. 200 x 25 x 12 x 6,75 meters.
Armament	3 triple 24cm 4 twin 12cm 8 twin 40mm several smaller guns
Protection
Belt	175mm
Deck	75mm
Turrets	200mm (24cm) and 60mm (12cm)
Torpedo bulkheads	30mm
Propulsion
SHP	90.000
Speed	29 kts. (28 kts. in tropical waters)
Weight	1750 tons
Note: Unfortunately, no sketch drawing (or any reference thereto) has been found.

It was appreciated that this vessel would be superior to a 20cm 10.000 ton cruiser, but had the important weakness that it could not avoid action with stronger opponents due to inferior speed. The protection also was felt to be insufficient. Consequently, the Navy strongly recommended against the construction of such a ship and nothing more was heard about the project.

In the meantime the German firms Deschimag and Germaniawerft started on detailed design work for the battlecruisers. propulsion plant. It is clear from the files that great problems were encountered in putting the required power into a ship of this size and still have a balanced design. Although the Germans succeeded rather better than the Dutch in limiting the area needed as much as possible, the Netherlands Navy remained to the end sceptical about using the rather complicated German plant. The Dutch feared that they would not have the necessary highly qualified personnel and overhaul capabilities available in the Netherlands East Indies if something went wrong with the plant. Therefore, they continued to prefer their own licensed built Werkspoor (Yarrow) boilers and Parsons turbines.

An undated tentative delivery schedule of about late 1939 was as follows:

Unit	Keel laid	Commissioning
1	1 February 1940	1 February 1944
2	1 July 1940	1 July 1944
3	1 December 1940	1 December 1944

During the fall of 1939, the Naval Construction Department, in collaboration with NEVESBU (and probably with the technical advise of the I.v.S.) worked out the detailed design specifications shown in Table 7.

Table 7 - Project 1047: Ca. October 1939
Hull Dimensions	A	B	C
Length at DWL (trial displacement)	230.00 m	235.00 m	240.00 m
Length at loaded waterline		235.60 m
Beam at DWL	30.00 m	30.00 m	30.00 m
Draft at DWL (trial displacement)	7.80 m	7.80 m	7.80 m
Draft at loaded waterline		8.15 m
Moulded depth (ships. side)	14.00 m	14.00 m	14.00 m
Moulded depth (centreline)		14.30 m
Displacement w/o attachments (trial displacement)	28.223.00 m³	28.283.00 m³	28.223.00 m³
Displacement with attachments (trial displacement)	28.811.00 T	29.251.00 T	28.811.00 T
Displacement w/o attachments (load displacement)		29.924.00 m³
Displacement with attachments (load displacement)		30.890.00 T
Midship section area (trial)		212.71 m²
Midship section area (loaded)		223.21 m²
Wetted surface with attachments		7340.00 m²
Midship section coefficient		0.909
Block coefficient		0.514
Waterline coefficient		0.665
Prismatic coefficient		0.565
Note: The 3 variants were developed to determine the most favourable dimensions and form coefficients. Variant B subsequently was selected to undergo towing trials at the towing tank at Wageningen (see below) and apparently was sused as a basis for all further work.

Weigh distribution (Variant B) in Metric Tons
I. Hull	7518.15
II. Armor (excluding revolving)	10620.00
III. Auxiliary equipment	888.00
IV. Main propulsion equipment	2972.00
V. Electrical	524.00
VI. Armament	3087.00
VII. Nautical equipment	70.50
VIII. Variable load	4946.36
IX. Margin	263.59
Normal load displacement	30890.00 T
Washington displacement (1.1016)	27940.00 t
Empty ship	26489.08 T
Armor Protection (as taken from Drawing Z 1 dated 27 October 1939)
Main side belt (waterline)	225mm on 50mm teak backing, located internally at 75^o angle.
Upper side belt	60mm tapering upwards to 30mm, angled at 75^o.
Longitudinal bulkhead	40mm
Main armored deck	75mm + 25mm
Upper armored deck	30 mm
Note: Other details unknown
Armament
Guns	9 x 28cm in triple turrets (120 rounds per gun) 12 x12 cm in twin turrets (200 rounds per gun) 16 x 40mm in twin mounts (1000 rounds per gun) 20mm or 12.7mm guns 2 aircraft
Machinery
SHP	180.000
Speed	34 kts.
Fuel	2700 tons.

	Project 1047 - General arrangement plan and profile (I) This drawing gives an cross-section overview of armor distribution. (Click on the drawing on the left. The link will open a new window)
	Project 1047 - General arrangement plan and profile (II) This drawing gives an cross-section overview of armor distribution. (Click on the drawing on the left. The link will open a new window)

Internal Arrangements
Accommodation of the propulsion plant was one of the main problems to be solved in the design, as has been seen above. Initially, about 84 meters ship.s length were assumed to be available, but it soon became apparent that this would not do if the ammunition supply was to be stored behind armor. During the succeeding months, after various schemes had been proposed, it was theoretically decided in March 1940, to fix the citadel length as follows:

Aft turret complex	ca. 17.25m
Aft electrical power station, computing center and pumping space	ca. 6.00m
Aft engineroom	ca. 15.75m
Aft boiler rooms (2 x 10.50m)	ca. 21.00m
Forward engineroom annex power station and pumping space.	ca. 15.75m
Forward boiler rooms (2x x 10.50m)	ca. 21.00m
Forward electrical power station and pumping space	ca. 6.00m
Various centers	ca. 6.00 m
Forward turret complex	ca. 31.50 m
Total citadel length	ca. 153.50m

Even this arrangement was not considered final because it was still not possible to provide sufficient protection to the ammunition storage. It is not apparent from the record if this problem was ever satisfactorily solved.

Model Trials
During February 1940 (or perhaps already at a much earlier date) model trials were held with the Variant B of the Naval Construction Department Design 1047 at Wageningen. Apparently, two models were tested: a Model No. 367 with a normal bow, and a Model No. 367A fitted with a bulbous bow. The characteristics of the ships representing the models would have been as follows according to the trial result report of 19 February 1940.

	Model 367	Model 367A
Length between pp.	235.00	235.00
Length at waterline (trial)	235.00	237.10
Beam at waterline (trial)	30.00	30.00
Mean draft (trial)	7.80	7.80
Displacement on frames	28283	28318.5
Displacement in salt water (1.025)	28990	29026
Wetted surface (naked)	6664	6686

It appears that the bulbous bow variant was considered the more satisfactory of the two, since the characteristics of Project 1047 as listed on Drawing Z-6 of 9 February 1940 reflect those measurements.

New weight calculations
During the period November 1939 through February 1940 some detailed work was done on the weight problem. A number of weight summaries were produced, unfortunately all undated. They are summarized below:

Table 8 - Project 1047 Weight Distribution
		(i)	(ii)
I. Hull		7080.359	7366.499
II. Armor (excluding revolving)		11216.738	11119.037
Belt (including bolts & wood)	2850.018
Upper deck	908.643
Main deck	2630.580
Longitudinal bulkheads	891.378
Transverse bulkheads	233.912
28cm barbettes	969.087
12cm barbettes	188.690
Control positions, etc.	296.951
Other	2247.479
III. Auxiliary equipment		937.752	937.752
IV. Main propulsion equipment		2936.350	2936.350
4 propellers, shafts, etc.	394.350
4 turbine sets, etc.	975.000
8 boilers, etc.	852.000
Other	715.000
V. Electrical		540.000	540.000
VI. Armament		3010.498	3012.000
three 28cm turrets incl. armor	2232.000
eight 12cm turrets	348.000
seven 40 mm twin AA	38.500
eight 20 mm single AA	9.600
2 sets paravanes	4.500
3 sets smoke makers	11.000
Searchlights (dia. 1500mm)	8.000
Searchlights (dia. 1200mm)	1.500
Fire control	150.000
Catapult	25.000
Other	182.398
VII. Nautical equipment		36.650	36.650
VIII. Variable load		4955.140	4955.140
Complement	172.940
Provisions	103.500
Washwater	110.000
Drinking water	99.000
Feed water	177.000
Fuel oil	2684.100
Diesel oil	84.000
Other liquids	264.500
28cm ammo (1080 rounds)	523.800
12cm ammo	96.000
40mm ammo	46.200
Machine gun and rifle	16.000
Other explosives	24.000
Chemical	2.000
Aircraft & Equipment	7.000
Water & oil in boilers and engines	440.000
Water & oil in piping	35.000
Various loads & ammo	88.100
Total		30713.717	30903.528

No detailed specifications for (ii) have been found. They do exist for (i) and it is assumed that (i) is the latter of the two, possibly giving the state of affairs as of about February 1940.

First Finalized Design
Probably as a result of the model test findings and other considerations (which unfortunately can no longer be exactly reconstructed due to the lack of reference material) Project 1047 came to some finalization by February 1940. At the least, a large number of detailed drawings were produced during this time, giving the particulars shown in Table 9.

Table 9 - Project 1047 (February 1940)
Displacement & Dimensions		Source
Length at DWL (trial)	237.10 m	Drawing Z 6 (11 Feb. 40)
Length between pp	235.00 m	Model test 367A
Maximum beam	30.44 m	Drawing Z.1 (27 Feb. 40)
Beam at DWL (trial)	30.00 m	Drawing Z.1 (27 Feb. 40)
Mean draft (trial)	7.80 m	Drawing Z.1 (27 Feb. 40)
Moulded depth	14.00 m	Drawing Z.1 (27 Feb. 40)
Trial displacement	28315.5 T	Drawing Z 6 (11 Feb. 40)
Armament	No. of guns
28cm in triple turrets	9	Drawing X 4 (16 Feb. 40)
12cm in twin turrets	12	Drawing X 4 (16 Feb. 40)
40mm in twin mounts	14	Drawing X 4 (16 Feb. 40)
20mm in single mounts	8	Drawing X 4 (16 Feb. 40)
(Aircraft & catapult not included)
Armor & Protection		Drawing Z 1 (27 Feb. 40) Drawing D1b (10 Feb. 40)
Main side belt	225mm inclined at 75^o (on 50mm teak with 18mm shell plating)
Upper side belt	40mm inclined at 75^o
Side belt forward	30mm tapering forward to 15mm
Side belt aft	30mm upper, 60mm lower
Longitudinal anti-torpedo bulkheads	40mm
Depth of main side belt	5.35m (2.10m below DWL, 3.25m above DWL)
Main armored deck	75mm + 25mm
Lower deck	30mm with 30mm inclines
Boiler uptakes	225mm gratings (main deck) and 75mm gratings (lower deck)
Lower deck aft	125-150mm protecting steering gear and propellers.
Transverse bulkheads	30mm + 15mm secondary forward. 200mm tapering to 40mm below main forward and aft
28cm barbette	250-200mm tapering to 40mm below
12cm barbette	75mm tapering to 60 mm
Turret armor	Not indicated
Conning tower	150 mm
Underwater protection	Double bottom depth 1.50m. Depth of side protective system 5.35m. Height of bulge compartment 9.60m. System consisting of air space-fluid air space compartments.
Machinery
SHP	ca. 180000
Speed	34 kts.
Radius	4500 NM at 20 kts.

	Drawing Z6 dated 9 February 1940 (design 1047 by NEVESBU) This drawing gives an overview of armament lay-out and the ships' general profile. (Click on the drawing on the left. The link will open a new window)
	Drawing Z1 dated October 27 1939 (I) (design 1047 by NEVESBU) This drawing gives a cross-section overview of armor distribution. (Click on the drawing on the left. The link will open a new window)
	Drawing Z1 dated October 27 1939 (II) (design 1047 by NEVESBU) This drawing gives a cross-section overview of armor distribution. (Click on the drawing on the left. The link will open a new window)
	Drawing D 1 b (I) dated 10 February 1940 (design 1047 by NEVESBU) This drawing gives profile overview of armor distribution. (Click on the drawing on the left. The link will open a new window)
	Drawing D 1 b (II) dated 10 February 1940 (design 1047 by NEVESBU) This drawing gives cross-section overview of armor distribution. (Click on the drawing on the left. The link will open a new window)

Further activities
During February 1940, apparently for the first time since the preliminary design had been drawn up in July 1939, serious attention was given to the idea of placing the side armor externally rather than internally (Table 9 still reflects internal side armor). So far, the detailed design drawings that can be located all gave the main belt in an internal position. However, according to a note dated 23 February 1940, the design drawing on this matter with external side armor was completed on that date. The final decision in this matter was postponed to study the outcome of a visit to Italy and the results of further talks with the Germans during February through April 1940.

Factfinding mission to Italy
The Dutch delegation visited the battleship Vitterio Veneto but were not allowed on board the Roma which was still under construction. The important result of this visit was that it was felt necessary to completely redesign the inner subdivision of Project 1047. The findings of the visit to Italy and further consultation with the Germans were discussed in project meetings during March and April 1940 in Holland, representatives of the Naval Construction Department and of the I.v.S. taking part. Unfortunately, only shorthand pencil notes appear to survive from these meetings, which can no longer be fully interpreted. However, the following points were noted:

(a) The central longitudinal bulkhead between the engine rooms was to be eliminated.
(b) The Italian suggestion to heighten the double bottom was considered very valid . especially with regard to the expected threat of future magnetic torpedoes . and some thought was given to the possibility of adding a second double bottom at 3 meters from the baseline (keel) with 25mm armor. However, it was found that the relatively shallow draft of the vessel would not permit this.

It was then decided to send a mission to Germany to talk over the problems again. This delegation took the design particulars, given in Table 10, dated 19 April 1940 along, which appears to represent the last design stage reached before the outbreak of war.

Table 10 - Project 1047 (19 April 1940)
Hull
Length between pp (at DWL)	236.00m
Length oa	241.20m
Maximum beam at DWL (outside armor)	29.40m
Maximum beam (upper deck)	30.85m
Moulded depth	14.00m
Trial draft	7.80m
Trial displacement (incl. armor)	28829.00m³
Trial displacement (incl. attachments)	29029.00m³
Trial displacement	29784.00 T
Normal load displacement	31396.00 T
Washington displacement	27988.00 t
Midship section area	216.20 m²
Midship section coefficient	0.943
Block coefficient	0.5326
Prismatic coefficient	0.5648
Waterline coefficient	0.642
Stability
Center of gravity	ca. 9.10m
Center of buoyancy	4.23m
Metacenter	11.89m
M . G	ca. 2.79m
Machinery	See chapter Propulsion plant
Armor & protection	(Drawing Z-17 dated 10 April 1940)
Main side belt	225mm inclined at 72^o (on 50mm teak with 17mm shell plating), external.
Upper side belt	40mm (vertical)
Longitudinal anti-torpedo bulkhead	40mm
Depth of main side belt	5.30m (2.10m below DWL, 3.20m above DWL)
Upper deck	20mm (?)
Main armored deck	100mm on 15 (?)mm deck plating
Lower deck	30mm with 30mm inclines
Boiler uptakes	225mm gratings (main deck) and 75mm gratings (lower deck)
Underwater protection	Bulge compartment below main side belt (depth 1.50 (?)m; double bottom depth 1.65m

Drawing Z-17 dated 10 April 1940 (design 1047 by NEVESBU)

This drawing gives an cross-section overview of armor distribution.

(Click on the drawing on the left. The link will open a new window)

Note: On 8 april 1940 a variant midship section also had been produced (Drawing Z-15) which included an internal side belt and showed the following differences with the data listed in Table 10.

Maximum beam at DWL	29.40m
Maximum beam (upper deck)	29.40m
Main side belt	225mm probably inclined at 72^o (on 50mm teak with 17mm shell plating), internal.
Upper side belt	40mm probably inclined at 72^o
Longitudinal anti-torpedo bulkhead	40mm
Depth of main side belt	5.55m (2.25m below DWL, 3.30m above DWL)
Upper deck	60mm teak on 30mm armor plating
Main deck	100mm on 13mm deck plating.
Lower deck	Estimated 30mm with 30mm inclines
Boiler uptakes	Not indicated
Underwater protection	Depth of side protective system 5.55m, depth of bulge 3.75m, system consisting of empty tank . empty tank . liquid tank.

Drawing Z-15 dated 8 April 1940 (design 1047 by NEVESBU)

This drawing gives an cross-section overview of armor distribution.

(Click on the drawing on the left. The link will open a new window)

About the author

J.S. Noot, LT Royal NL Navy

Lt. Noot is 33 years old, married with no children. He entered the navy in 1966 and was commissioned as a lieutenant j.g. in 1968, and spent some time serving on board Hr.Ms. Karel Doorman. After that, he was posted to the Ministry of Defence in The Hague as research analyst, in which capacity he is still employed. His main hobby is the study of naval ships since the introduction of steam, and over the years has collected a vast amount of books and other material on the subject. He joined our organization 6 years ago, but has been fortunate in taking over from a deceased person an almost complete collection of all the W.I. issues that have appeared since it was first published. He is also a member of the World Ship Society.

- End of article -

Note by webmaster
This article is a reproduction of the original article published in Warship International No.3 of 1980. Alterations of the original article have only been made with regards to the lay-out and some photo descriptions, the contents are otherwise original. This article does not include new facts which may have come to light since the article's publication in 1980.

This article is reproduced with the kind permission of Warship International. Copyright © 1980 International Naval Research Organization (http://www.warship.org)

December 24, 2009 Created page

Back Home