Vessel keeled over in dry dock

[Michael Black]

The MV Petrel has rolled over on the keel blocks in Imperial dry dock Leith. It appears to have slipped over and is lying on its starboard side against the dock wall.
Not known if any injuries as yet.
Hope everyone is OK. Press blaming gales in the area?!!!! Source BBC news. Unfortunately now reports of multiple injuries
Regards Michael

[j.sabourn]

Always when entering a dock or leaving it the most dangerous stability is when the keel initially touches the blocks aft. Immediately the metacentric height changes and in all probability the vessel is unstable , that is why the ship should be trimmed inches at least by the stern and its gm worked out before entry into the dock , when coming out of dock all weights on board should be the same as going in if no problems were observed . It is not the first time a vessel has tipped in drydock and won’t be the last , that first touching of the blocks is the critical time . A floating drydock on the other hand a lot of these dangers are limited as the dock comes up to meet the vessel the other way round. As mate in the old days if you had your figures worked out wrong you would have found yourself jobless. Cheers JS

[Ivan Cloherty]

I have noticed a tendency over the last few years with vessels having a more flat bottomed profile that the use of dockwall side shores has disappeared and the tendency is to use bilge keel shores to the dock bottom. Not saying this was the cause of the incident, but just an observation.

For those not familiar with dry dock procedures (of the past) a shore is a substantial (usually 12" x 12") of various lengths of timber, which span the gap from the vessels side to the dock wall and are placed in position port and starboard whilst the vessel is afloat and prior to just settling on the blocks at the bottom of the dock, this prevents the vessel taking a list or falling over. Bilge keel shores are short lengths of timber (12" x 12") placed on the underside of the vessel at its extremities extending from the hull to dock floor, however these cannot be placed until the dock is dry. Some modern drydocks have port and starboard cradles adjacent to the keel blocks which are in place before the dock is dry, these also prevent the vessel listing or falling over.

Not trying to teach anyone to suck eggs just trying to help non seafarers understand the methods of keeping a vessel stable whilst high and dry.

[Keith Tindell]

Reports states about 25 persons injured, looks to be pretty serious. I wonder what the procedure is to reflect her ?, obviously after major inspections. kt

[Ivan Cloherty]

Reports states about 25 persons injured, looks to be pretty serious. I wonder what the procedure is to reflect her ?, obviously after major inspections. kt

There is a photo on the internet and the angle of loll seems to be about 35/40 degrees, so if she went over suddenly and people working on board they would have been catapulted sideways into all kinds of objects when least expecting it.

[Marian Gray]

#5, https://www.msn.com/en-gb/news/world...2e329c55&ei=22

[John Arton]

From the state of the hull paintworks it would appear that she was in the process of the dock being flooded prior to her leaving the dock. Anchor and cable run out which is normal for undocking from drydock, anchor and recovered once off the blocks.
Rgds
J.A

[Jim R Christie]

From the state of the hull paintworks it would appear that she was in the process of the dock being flooded prior to her leaving the dock. Anchor and cable run out which is normal for undocking from drydock, anchor and recovered once off the blocks.
Rgds
J.A

The dock was still dry apparently.
The anchor and cable appear to be on the dock bottom with a wire running up through the pipe; they would not have waited until she was afloat to recover it, that would have all been done prior to final inspection long before flooding up.
The Dales Marine staff know their stuff and the Dockmasters in particular work in all of their drydocks as the workload takes them (they have five all told), moving from docking to docking etc so no shortage of experience there.
She'll have had the usual three rows of keelblocks beneath her and I can see from pictures online that she had timber shores against the hull too, presumably because she has a very rounded bilge as they're otherwise very rare these days unless a vessel has a particularly fine hull form. I can't even remember the last time I saw a keelshore as proper keel blocks are now universally used on the bottom, even for the outer blocks.
The wind today was blowing 60+mph in Leith and the orientation of the drydock would have put the wind right on her port beam.
It'll be interesting to see the outcome of the HSE investigation as the only other vessel I can remember this happening to was a brand new RFA tanker about 20 years ago and that was a straightforward BAE cock up.

[Alan Mcdougle]

I remember this happing in the late 1950 at Smiths Dock North Shields a tanker Vardellfied had just been launched at Blyth Shipyard can not remember why it happened but tank testing was rum

[Ivan Cloherty]

Also happened to one of Trinder Andersons in Belfast in the 60's, think it was the 'Antrim'

Many Soviet/Russian vessels have suffered from this illness