Lifting the lid on davit regulations

NORSOK

Davit regulations are many, varied and can differ according to use and industries. If you are in need of a workboat davit for seismic operations, or whether are you working in the petroleum industry, there are different standards for you to be aware of.

Let’s face it, striking the right balance can be tricky for regulators: if a standard is too low, why bother having it? If it’s too high, inflexibility can result, or the temptation can grow to work around the rules.

Even so, regulatory oversights involving high visibility objects can’t be simply ignored. Look high up on any ro-ro ferry, for example; it’s hard to miss the Fast Rescue Boat and its supporting FRC davit and the prominent location is by law, under IMO rules devised after the Estonia tragedy in 1994. MS Estonia sank in the Baltic Sea I 1994. It is, after the Titanic, the second-deadliest European shipwreck disaster to have occurred in peacetime and 852 lives were lost.

SOLAS and davit hoisting speeds

The Safety of Life at Sea Convention (SOLAS) also has strong views on the speeds at which davits can hoist (18m/min) and lower (36 m/min) boats, but it has nothing to say about the relationship between these speeds and the sea states in which boats are launched and recovered.

However, crew boats are not actually considered life-saving appliances in the narrow SOLAS sense. Actually, davit systems performing at the bare SOLAS minimum would mean an unpleasant ride for those on the crew boats being lifted and lowered in day-to-day operations. A boat hoisted free from the water at 18m/min in a down-swell will be lifted again by the following wave crest, causing the hoisting wires to go slack. When that wave subsides, the boat drops, with those on board getting a nasty jolt.

Different speeds for different sea states

All Vestdavit davits can be supplied with hydraulic shock absorbers, self-tensioning, dynamic brakes and hook in boat. These features mean that single point davits from Vestdavit can be lifted and lowered at different speeds to address different sea states – Sea state 1: 18m/min; 2-3: 36m/min; 4: 40m/min; 5-6: 50m/min. Dual point davits operate over the same speed ranges, with the addition of 60 m/min launch and recovery lifting/lowering speeds in sea state 7.

Vestdavit strives to look beyond SOLAS for guidance on equipment safety.

NORSOK Standards for the petroleum industry

Far more stringent are the NORSOK R002 Standards, developed by the Norwegian petroleum industry. NORSOK R002 require all new davits on offshore installations in Norwegian waters to comply by these regulations.

Key elements of the regulations are requirements for a dual independent winch brake system, hoisting speed, davit cylinder redundancy, reinforced davit structure, hydraulic power pack and electrical cabinet built-in compliance with EX zone regulations.

The Vestdavit D-5000 NORSOK R-002 compliant davit is already in use in the Norwegian sector of the North Sea for major operators. This davit includes all mandatory safety features. The HPU, valves, control systems, electronics cabinets and back-up accumulators are all mounted on a separate skid. This system is delivered fully FAT tested with DNV verification prior to delivery. This will greatly simplify yard installation, eliminating hot-work in the installation, saving time and cost.

Vestdavit has a full range of NORSOK compliant davits:

  • D-5000 – the 5 tonnes SWL NORSOK R002 fixed A-frame davit designed for FRCs boats;
  • PLR-6000 – the 6 tonnes SWL NORSOK R002 pivoting A-frame davit for FRCs includes all mandatory safety features;
  • HN-16000 – for FPSOs and other floaters working in the Norwegian North Sea, which also need NORSOK-compliant lifeboat davits.

In meeting these demanding new standards, Vestdavit also notes that the API 2 regulations due to apply in US waters have many of the same requirements.

Vestdavit is also the first to offer the new HN-16000 two-point lifting davit for lifeboats. The marine davit has a SWL of 16 tonnes, and can be adapted to many types of lifeboats.

 

Are you interested in NORSOK compliant davits? Contact our development director here!