Styrbjørn under tow with Thor III leading in front on their way to Horten.

Styrbjørn:
Call sign: LHBW (earlier JSBV/SGQD)
Build. Nr: 318 - Göteborgs Nya Verkstad, Gothenburg Sweeden
Year of build: 1910
Gross tonnage: 167 grt.
Length: 29.42 meters
Engine: 550 hp, ( 410 kw ), Coumpound steam engine
Engine control: Stephenson slide. (Stephenson link valve gear for controlling the forward/backward motion)
High pressure cylinder: 18'' (46cm)
Low pressure cylinder: 35,5'' (85cm)
Stroke: 24'' (61 cm)
Speed: 12 knots
Boiler: Coaldriven scottish smoke tube boiler
Length: 3,2m
Diameter: 3,95m
Heating surface: 159m2
Pressure: 9.14 kp/cm2 – 130psi
Coal consumption: ca. 550 kg/hour
Registered owner: Norsk Veteranskibsklub, Oslo
Port of registry: Oslo

Thor III
Imo: 8876481
Call Sign: LDUF
Gross tonnage: 292
Max. Length: 35,070m
Breadth: 9,3m
Depth: 4,8m
Type of ship: Icebreaker/tug
Year of build: 1960
Flag: Norway
Homeport: Drammen