STOREBRO Passion - information about STOREBRO Royal Cruisers

Remarks

The Storebro Royal Cruiser 31 was the smaller sister of the successful Royal Cruiser 34. At the same width it was about one meter shorter.

With the Storebro Royal Cruiser 31, the three variants Adriatic, Biscay and Baltic were offered for the first time.

Adriatic - The open version with large cockpit and without hardtop. Later built boats (the "de Luxe" version) were equipped with a radar arch.
Biscay - The first Biscay of Storebro was the bad weather variant of the Adriatic with hard top and sliding door. The sofa in the salon could be folded down to a bunk bed. The Biscay was also available with flybridge.
Baltic - The direct little sister of the well-known Storebro Royal Cruiser 34. Available with or without hardtop.

The original concept of the Storebro Royal Cruiser 31 only included the variants Adriatic and Biscay. Both versions based on the same deck shell. For the Mediterranean in particular boats with Biscay-hardtop but without sliding-door were built. Some customers also upgraded their Adriatic by using the Biscay-hardtop.

First Storebro Royal Cruiser 31
Baltic based on Adriatic

Only because of the urging of a customer of Ivar Gustafsson an Adriatic was rebuilt to Baltic from boat builders of the yard, but not for the shipyard order, the shipyard management decided to develop a complete additional GRP deck shell for the model Baltic. The prototype of the Baltic was created with add-on parts made of wood.

The boat was completely made of GRP, apart from the mahogany made hardtop. On first boats the wooden parts were painted in the color of the gelcoat. Due to the feedback from the customers, the wood was clearly varnished in typical Storebro manner later.

Engines
For the Storebro Royal Cruiser 31, essentially the same motors were used as for the somewhat larger Storebro Royal Cruiser 34. So at the beginning, Volvo Penta MD32, Perkins and Chrysler engines were used. Due to strikes in England, the supply of Perkins engines was almost impossible. At this time, Volvo Penta launched the TAMD60A with 192 hp on the market. The TAMD60x series then replaced the Perkins engines.
The originally offered Volvo Penta MD32 were only offered with left turning propellers. It was different with the Perkins engines. Here in each case a left and a right-turning engine was installed. The right turning engines were marked by an additional "X" in the serial number (e.g. 354UX...). Later installed Volvo engines had suitable transmissions for left or right hand rotation.
By default the Storebro Royal Cruiser 31 was delivered with two engines and shaft drive. However, a few boats were also equipped with single engine and shaft drive.
Seven ships were equipped with sterndrive. Five of them received the Volvo Penta AQD40A with 124 hp. The engines were then coupled with 250 or 280 singleprop drives. 1983 a 31er with two Volvo Penta AQ200D V8 engines and 280-drive was delivered. Last ship was then 1983 a ship with two AQAD30 engines and the new DuoProp drive.

Layouts
Obviously, there are two layout options:

The first variant consisted of a living room with a large L-shaped sofa, whose back could be folded to produce a large bed in the bow. There was no spatial separation to the forecabin.
Boats from 1976 onwards had the layout with U-Dinett and V-berth in the bow known from the Storebro Royal Cruiser 34.

Equipment
From 1985, the Storebro Royal Cruiser 31 was also offered as a "de Luxe" version. The "de Luxe" package contained the following extra equipment: white hull and deck, mahogany on railing aft, plates with model name in mahogany - colour stripes on freeboard - extra skylight over galley - special colour upholstery - special bases for helmsman and navigator seat allowing them to swivel 360 degrees and with height adjustment (Adriatic and Baltic only) - extra removable navigator´s seat (Biscay only) - spring bollards amidships - mahogany on horizontal surface inside front windows - extra glassholder at helmsman´s position - on Adriatic and Baltic, extra lights on sidepanels to port and starboard behind helmsman and navigator seats - if radar mast is fitted the lights will be installed in this - on Biscay, extra cockpit lights are installed under roof behind the sliding door.

Hull

Storbro Royal Cruiser 31
with original hull

When the first Storebro Royal Cruiser 31 were fitted with flybridges, it became apparent that the ship tended to have unstable handling. This manifested itself in the fact that the higher centre of gravity made the ship more unstable laterally and it oscillated more easily around the longitudinal axis when the weight was shifted. At full speed, the ship tended to overtrim (the same phenomenon later occurred with the SRC 395 equipped with Yanmar engines).

Modified hull of the Storebro Royal Cruiser 31

As neither the shipyard nor the customers were satisfied with the situation, the hull was reworked. Previously produced ships were reworked and with construction number 2968 (1984) all Storebro Royal Cruiser 31 received the new hull. This could be recognised by the tear-off edges in the bow area and the water deflector that was pulled further down aft. The hull lost a little of its rounded bulkhead characteristic, became wider aft under water and resembled a V-hull a little more.
The new hull essentially brought advantages for the ships equipped with a flybridge.

Miscellaneous

The Royal Cruiser 31 was made with gelcoat in a light shade of yellow. This was also available for the Royal Cruiser 40. At the presentation of the prototype at the Hamburg-fair, the visitors gave a negative feedback concerning the originally white gelcoat.
The Royal Cruiser 31 was originally also offered with one engine. This was a measure to compete successfully with a competing model whose merits should be the very low price. In direct comparison, the much-quality processed Royal Cruiser 31 turned out as the better offer.
The brochure of 1984 shows the old layout in the bow of the 31 Biscay when looking into the deck saloon.
The anchor-catapult shown in the brochure is on a Royal Cruiser 38.
The German Wasserschutzpolizei had a modified Biscay named "Warder" on duty. The boat was equipped with twin TAMD 60B.

Licensed boat building
After the start of cooperation with Libya to build up local water sports 15 Royal Cruiser 31 were delivered from Sweden. 65 Royal Cruiser 31 were built later in Libya under production license. These ships were intended exclusively for the Libyan market.

2021-03-18

Photos and images

Building and testing

Storebro Royal Cruiser 31 Baltic with single engine

Storebro Royal Cruiser 31 Biscay modified for the German Wasserschutzpolizei (S/N 2720 - 1981)

Custom-built boats

Additional Photos

In some cases, further images of registered ships are available for registered users.

Engines

Engines		Chrysler 225LM318BW	Thornycroft T 345	Perkins T6.354 MGT	Volvo Penta MD32A	Volvo Penta TAMD60A	Volvo Penta TMD40A	Volvo Penta AQD40A	Volvo Penta BB225 D/E/F
Production					1970-1977	1976-1978	1976-1985	1977-1985	1977-1986 ^*
Fuel		Diesel	Diesel	Diesel	Diesel	Diesel	Diesel	Diesel	Petrol/Gasoline
Stroke		4	4	4	4	4	4	4	4
No. of cylinders		8	6	6	6	6	6	6	8
Bore	[mm]	99.30	98.00	98.40	90.00	98.43	92.00	92.00	95.00
Stroke	[mm]	84	125	127	83	120	90	90	88
Compression ratio		8.5:1	16.8:1	15.5:1	22.1:1	16.0:1	21.0:1	21.0:1	8.5:1
Displacement	[l]	5.20	5.66	5.80	3.17	5.48	3.59	3.59	5.00
Torque	[Nm]
Engine output	[kw/(HP)]	136/(185)	71 - 83/ (97 - 113)	129/(175)	57 - 78/ (78 - 106)	89 - 147/ (121 - 200)	91/(124) ^***	67 - 91/ (91 - 124)	165/(225)
Rotations	[1/min]	4000	2500	2400	4000	1800-2800	3000-3600	3600	4400
Weight	[kg]		617 ^****		395	750	440

Engines		Volvo Penta AQ200D	Volvo Penta TAMD60B	Volvo Penta TAMD40A	Volvo Penta TAMD40B	Volvo Penta AQAD30A	Volvo Penta TAMD60C	Volvo Penta TAMD41A	Volvo Penta TAMD 31A
Production		1977-1986	1978-1983	1980-1985	1983-1986	1983-1986	1983-1987	1986-1989	1986-1991
Fuel		Petrol/Gasoline	Diesel	Diesel	Diesel	Diesel	Diesel	Diesel	Diesel
Stroke		4	4	4	4	4	4	4	4
No. of cylinders		8	6	6	6	4	6	6	4
Bore	[mm]	95.00	98.43	92.00	92.00	92.00	98.43	92.00	92.00
Stroke	[mm]	88	120	90	90	90	120	90	90
Compression ratio		8.5:1	16.0:1	21.0:1	21.0:1	21.0:1	16.0:1	16.0:1	16.0:1
Displacement	[l]	5.00	5.48	3.59	3.59	2.39	5.48	3.59	2.39
Torque	[Nm]						625
Engine output	[kw/(HP)]	147/(200)	103 - 169/ (140 - 230)	81 - 109/ (110 - 148) ^***	116/(158) ^***	81/(110)	112 - 184/ (152 - 250)	147/(200)	96/(130)
Rotations	[1/min]	4400	1800-2800	3000-3600	3600	3800	1600-2800	3800	3800
Weight	[kg]		750	485	475		680 ^****	465
^* All variants of this engine
^*** Power at the propeller shaft
^**** Weight without gearbox

Attention:
The values given in the motor diagrams below are measured values of individually equipped ships. The measured values can vary depending on the equipment as well as the wind and temperature conditions. These values do not indicate a binding property, but can only serve as indications.

As a registered user, depending on the type of boat, you have access to further diagrams regarding consumption, range and noise level.

Statistics

As a registered user, you have access to further diagrams on hull colours, layout variants, type of wood used and production figures per year, depending on the type of boat.

Technical development

As a registered user, you have access to the list of changes in production, depending on the type of boat.

Legend:
	PDF-file available for download		PDF-file not available for download		PDF-file only available for registered users		PDF-file only available for registered owners		PDF-file only available for SRCC members

Brochures, flyer		Low	Hi
Royal Cruiser 31 - Brochure	1975
Royal Cruiser 31 - Kit - Flyer	1975
Royal Cruiser 31 Baltic - Brochure	1976
Royal Cruiser 31 flybridge - Flyer	1980
Royal Cruiser 31 - Brochure	1980
Royal Cruiser 31 - Brochure	1984
Royal Cruiser 31 - Brochure	1985
Royal Cruiser 31 - Brochure	1987

Pricelists		Low	Hi
Storebro Bruks AB - No. 49 - Pricelist	1976
Storebro Bruks AB - No. 50 - Pricelist	1976
Storebro Bruks AB - No. 51 - Pricelist	1977
Storebro Bruks AB - No. 53 - Pricelist	1978
Storebro Bruks AB - No. 55 - Pricelist	1979
Storebro Bruks AB - No. 59 - Pricelist	1980
Storebro Bruks AB - No. 60 - Pricelist	1981
Storebro Bruks AB - No. 63B - Pricelist	1983
Storebro Bruks AB - No. 65 - Pricelist	1984
Storebro Bruks AB - Nr. 67B - Pricelist	1985
Storebro Bruks AB - No. 69 - Pricelist	1986
Storebro Bruks AB - Nr. 70 - Pricelist	1986

Complete brochures		Low	Hi
Storebro Bruks AB - Complete brochure	1978
Storebro Bruks AB - Complete brochure	1985
Storebro Royal Cruiser - Complete brochure	1990

Manuals		Low	Hi
Royal Cruiser 31 - Owner´s Manual	1985

Storebro - Technical documents			Low	Hi
Storebro Royal Cruiser 31 - Adriatic section		1975
Storebro Royal Cruiser 31 - Biscay layout	B-2210	1975
Royal Cruiser 31 - Transportdocument	4-5050-0001	1975
Storebro Royal Cruiser 31 - Baltic layout	B-2610-3	1976
Storebro Royal Cruiser 31 - Baltic section	B-2611-0	1976
Storebro Royal Cruiser 31 - Baltic sideview	B-2609-3	1976
Storebro Royal Cruiser 31 - Biscay layout	B-2266-3	1976
Storebro Royal Cruiser 31 - Biscay sideview	B-2267-3	1976
RC 31 - Wiring diagrams (VP TAMD60)		1977
RC 31 - Wiring diagrams (VP TAMD60A) ST:B Original	B-2871	1977
RC 31 - Wiring diagrams (VP TMD40)	B-2873-0	1977
Royal Cruiser 31 - Main switch panel connection	4-5008-0002	1978
SRC 31 - Fuse- and cableno.list	3100779	1979
RC 31 - Wiring diagrams (VP TMD40)	0-5008-0018	1980
Royal Cruiser 31/34 - Steel cradle dimensions	2-5050-0009	1983

Storebro - Test Reports			Low	Hi
Royal Cruiser 31 Biscay - Test Report Volvo Penta TMD 40A (S/N 2430)		1979
Royal Cruiser 31 Biscay - Test Report Volvo Penta TAMD 40A (S/N 2573)		1980
Royal Cruiser 31 Adriatic - Test Report Volvo Penta TAMD 60C		1984
Royal Cruiser 31 Adriatic - Test Report Volvo Penta TAMD 41A		1986

Technical brochures - Manuals			Low	Hi
Chrysler 225 - Operating Manual
Ford 2704ET series with turbocharged engine - Manual
Ford 2710 series with turbocharged engine - Manual
Ford 27xx - Service Manual
Perkins Engines 4.108/4.236/(T)6.354(MGT) - Operators Manual
Perkins Engines 4.108/4.236/(T)6.354(MGT) - Operators Manual
Thornycroft T345 - Instruction Book
Thornycroft T345 - Repl. Parts List
Twin Disc Marine Transmission MG-502 Workshop Manual
Volvo Penta MD21A, MD32A, AQD21A, AQD32A - Workshop Manual
Volvo Penta MD21A/MD32A - Manual
Volvo Penta MD21A/MD32A - Manual
Volvo Penta TAMD40B MS3C - Manual
Volvo Penta TAMD41A/B MS4A - Manual
Volvo Penta TAMD60A/B, TAMD70C/D - Manual
Volvo Penta TMD40A, TAMD40A - Manual
Volvo Penta TMD40A, TAMD40A - Workshop Manual

Technical brochures			Low	Hi
Thornycroft T345 - Productflyer
Twin Disc MG 502/MG 502-1 brochure
Volvo Penta - Program 1989
Volvo Penta TAMD 40A - Productflyer
Volvo Penta TAMD 40B - Productflyer
Volvo Penta TAMD 60B - Productflyer
Volvo Penta TAMD 60C - Productflyer
Volvo Penta TMD 40A - Productflyer

Reviews			Low	Hi
Neptune-Nautisme - Royal Cruiser 31 - Review		1976
MBY - Royal Cruiser 31 - Review		1977
Australian Sea Spray 02/82 - Royal Cruiser 31 - Review		1982
Australian Boating 02/82 - Royal Cruiser 31 - Review		1982
Båtliv - Royal Cruiser 31 - Review		1982

Multimedia documents			Low	Hi
Storebro Royal Cruiser		1981
Storebro Royal Cruiser		1981
Storebro Royal Cruiser		1981

Newspaper articles			Low	Hi
Perfectest exhibition prototype - Storebro Royal Cruiser 31		1975
What a speed with diesel!		1976
Praktisk Båtägande - Storebro 31 Baltic		2020
Dagens PS - Storebro 31 - Swedish quality boat that stands up		2021

Technical Data
Year of production	1975-1991
L.o.a. [m]	9.30
Beam [m]	3.20
Draft [m]	0.95
Height above waterline [m]	2.25 2.55 - Biscay
Freeboard front [m]	1.20
Freeboard aft [m]	1.05
Displacement [t]	4.00 - 6.00
Fuel [l]	2 x 325
Water [l]	2 x 140
Voltage [V]	12
Hull	GRP

Number of boats	480

Designer	Winfried H. Wilke