Storebro Royal Cruiser 31 Adriatic/Biscay/Baltic

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.

• In the Swedish film "Götakanal", the Storebro Royal Cruiser 31 Baltic S/N 2649 was used as a product of one of the two competing shipyards called Uniship. For the filming, the ship was equipped with two Volvo Penta TAMD 60Bs and had a second steering position in the saloon as a special feature, so that the ship could be driven from there while the actors only played their roles in the cockpit. After the end of filming, the ship was fitted with Volvo Penta TMD 40A engines, converted back to normal standard and sold to a Swedish customer.
• 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.
• Several Biscay and Adriatic boats were delivered with larger tanks. These boats were fitted with the 500 litre tanks installed in the Storebro Royal Cruiser 34. This option was not possible for the Baltic variant, as the engine compartment was too short due to the recess for the berths in the aft cabin.

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.

2024-02-10

Technical development