ASTRA is a super strong expedition vessel that can go anywhere in the world, regardless of the weather.
In Dag Pike’s article on ASTRA in Passagemaker magazine in March 2018 he said:
“...I would put this 80-footer in the category of the ultimate passagemaker - a vessel capable of taking on the world’s toughest oceans and coming out on top. She has to be one of the toughest boats of her size ever built... with traditional sheer lines and purposeful superstructure. No frills here, just a proper functional boat built for one of the toughest jobs in the world”.
Read Dag Pike’s article here: “A Proper Little Ship – The Rugged ASTRA”
ASTRA is a 23.35 metre customised polar expedition vessel with the highest ice class rating and ice breaking capability. All this on a vessel that is just below 24 metres in length and also European CE certified.
According to construction drawings on board (and confirmed by thickness measurements carried out during the survey in September 2020), the hull shell plating thickness varies from 15mm on the bottom plates tapering through 13, 11 and 9mm on the outer shell plating and deck areas. UTI testing (Sep 2020) indicated less than 4% reduction in the original shell plating, in part attributed to ASTRA having operated in fresh water in the Baltic for her initial 22 years.
She is powered by a low/medium speed Mitsubishi main engine (M.E.) of 1,350 BHP, that is started by compressed air at 30 Bar, in the same manner as a merchant vessel. You do have to remember that ASTRA was built as strongly as was feasible for a vessel of her size and she is a big step up from the small scale electrics and battery starts commonly found on other vessels below 24 m.
The M.E. goes through a 3:1 reduction gearbox, reducing the RPM at the propeller to 1/3 of that at the M.E. The propeller shaft is approx. 12” in diameter and, on seeing it, you start to get a real sense of her strength and design capability for adverse weather. The propeller itself is a 4 bladed controllable pitch propeller (CPP) of 1.72 m in diameter and the rudder is a high performance Schilling rudder (+/- 64°) that can be operated either hydraulically or electrically.
The Schilling rudder, combined with a 100kw hydraulic bow thruster, provides incredible manoeuvrability for a vessel of ASTRA’s size. Fitted with 4 conning positions from the navigation bridge, the vessel can be handled from Port, Centre and Starboard (looking forward) and the centreline aft when manoeuvring astern.
Anyone that has ever owned a SAAB or VOLVO will have had the opportunity to appreciate Swedish engineering. A substantial hydraulic system is at the heart of the ship’s systems on ASTRA and hydraulics power the following systems:
- Bow Thruster
- Anchor Windlass
- Towing Winch
- Stern Flap
- Forward Crane
- Aft Crane
- Fire Pump
The key systems on board are provided with a back-up system that provides 100% redundancy, including:
- Bilge Pumps
- Air Compressors
- Power Generation.
Built as a rescue vessel, ASTRA is incredibly stable and has no ‘point of vanishing stability’. When fully laden, with all tanks full, she still has a GM of 0.98m.
In addition to air conditioning, ASTRA has substantial heating capability from her CTC boiler (that can run electrically or from diesel) and is very cosy onboard, with ample heating radiators and lots of hot water. Heating is one of the areas where her ice class comes in to play, with heating blowers in the foc’sle store and steering flats, hot water discharge points from the engine cooling discharge to deck if required for clearing ice (lancing) and, running just below the bulwarks, is a heating coil for clearing ice from the scuppers. This has stainless steel pipework, as is common for the majority of systems onboard.
During ASTRA’s refit in 2017, aside from the work you might expect in a repair period, the following major additions were made:
- Air conditioning in all areas
- new Portuguese bridge
- new Furuno navigational equipment
- new 4 automatic rotating stabilisers
- large additional battery banks (to be able to lie at anchor without auxiliaries)
- increased fuel capacity
- fresh water maker
- new oak flooring
- new toilet and shower facility on the lower deck
With the new MagnusMaster rotating stabilisers fitted in Sep 2017, during the voyage across the Bay of Biscay, ASTRA encountered swells from astern of 4-5 metres in height and it was remarked that “...this went largely unnoticed, with coffee cups staying firm on the table and the passengers able to get on with their normal activities. The vessel was only moving steady slightly up and down without rolling side to side”.
Sea trials off Lagos, Portugal
Looking aft in the engine room
Propeller shaft (Note the size of a foot for scale)
The hydraulic system with the main switchboard in background
Centre and starboard bridge conning positions
Controllable Pitch Propeller and Schilling rudder, also showing the
retracted stabiliser on the port quarter