Rescue 116 Crash at Blackrock, Co Mayo(Mod note in post 1)

Big Nasty · 31-03-2017 07:24AM

Surely it won't 'fall out' until it reaches the surface?

Panrich · 31-03-2017 07:33AM

Big Nasty wrote: »

Surely it won't 'fall out' until it reaches the surface?

It's not like a bucket though where the water contained inside has nowhere to go. The water will flow out and be replaced on a continuous basis as it is being raised. I'm not sure what precise effect this has on the weight being raised but you'd imagine that it would be easier to lift a sieve than a bucket through water.

ratracer · 31-03-2017 08:01AM

Why is it ok to speculate on whether a professional salvage operator, in conjunction with all on site services, will be able to successfully complete their job?

Cloudio9 · 31-03-2017 08:13AM

Boaty wrote: »

The lift is outside the capacity of the 20 tonne crane of the le Granuaile
The helicopter weight is approx 5 tonnes, a quick Google tells me that the volume of the cabin of an S92 is roughly 24m3. 1m3 of water is 1 tonne, I'll let you do the math.

The salvage company will have the equipment and the knowledge to get the fuselage up safely and without destroying it.

Probably for the best Boaty

Ludo · 31-03-2017 08:48AM

mulbot wrote: »

So speculation is ok on the thread now?

Looks like it is fine as long it is questioning/speculating about knowledge of boat people rather than aviators.

Steve wrote: »

I've been on one, I know.

Gadgetman496 · 31-03-2017 09:24AM

The Ocean Challenger made good ground overnight, she's parallel with Carna off the Connemara coast Galway.

challengemaster · 31-03-2017 09:32AM

Steve wrote: »

I can find out for sure but it will take a day or two, Pretty sure that crane would not be up to lifting 5000kg+ from the sea floor in open sea.

I could be wrong, that's only my opinion.

Atlantic Towage & Marine were contracted to undertake the salvage operation with their tug the Ocean Bank. On arriving at the scene skipper Sean Harrington and his crew secured a line onto the 100ft yacht, and towed her into a sheltered inlet off Barley Cove Beach. Divers inspected the yacht’s hull, and the decision was made to remove all rigging and the mast before lifting her. Using the recently fitted deck crane which can lift up to 30 tonnes, the delicate operation of lifting the yacht backed up with airbags and compressors commenced

http://www.atlantictowage.com/rambler-100-super-yacht-salvaged/

I can't imagine they would fit a lesser crane to a newer vessel in their fleet. Nor would they send an inadequate vessel for the job when they have one with 30 tonne lifting capacity.

Calina · 31-03-2017 09:34AM

Ludo wrote: »

mulbot wrote: »

So speculation is ok on the thread now?

Looks like it is fine as long it is questioning/speculating about knowledge of boat people rather than aviators.

Steve wrote: »

I've been on one, I know.

Tbh i think there is a difference between speculating on the load bearing capabilities of a boat versus the actions of dead people which may or may not have led to their demise. But ymmv.

Tabnabs · 31-03-2017 09:41AM

challengemaster wrote: »

http://www.atlantictowage.com/rambler-100-super-yacht-salvaged/

I can't imagine they would fit a lesser crane to a newer vessel in their fleet. Nor would they send an inadequate vessel for the job when they have one with 30 tonne lifting capacity.

The Granuaile crane has a 20t capacity

I'm not seeing anything in the Atlantic towage fleet with gear that big.

I think the tug may be used in conjunction with the expertise of their personnel to raise the chopper and float it out into deeper water where it can be transshipped to a barge or the deck of the Granuaile/similar.

Time will tell.

sword1 · 31-03-2017 09:46AM

Tabnabs wrote: »

The Granuaile crane has a 20t capacity

I'm not seeing anything in the Atlantic towage fleet with gear that big.

I think the tug may be used in conjunction with the expertise of their personnel to raise the chopper and float it out into deeper water where it can be transshipped to a barge or the deck of the Granuaile/similar.

Time will tell.

Nail, head I think, it will be floated with airbags and maybe Pumped out before lifting on to the Granuaile. This is pure speculation I have no idea or have heard of any plan but it seems logical

challengemaster · 31-03-2017 09:50AM

Tabnabs wrote: »

The Granuaile crane has a 20t capacity

I'm not seeing anything in the Atlantic towage fleet with gear that big.

I think the tug may be used in conjunction with the expertise of their personnel to raise the chopper and float it out into deeper water where it can be transshipped to a barge or the deck of the Granuaile/similar.

Time will tell.

So you think they're lying on their own website about their fleets capabilities?

Tabnabs · 31-03-2017 10:43AM

challengemaster wrote: »

So you think they're lying on their own website about their fleets capabilities?

Oh no, please report me to the internet police! :eek:

That is not a thirty tonne crane. I'm licences to operate a ships crane of up to fives tonnes capacity and it was significantly bigger than that thing.

elastico · 31-03-2017 10:48AM

Tabnabs wrote: »

Oh no, please report me to the internet police! :eek:

That is not a thirty tonne crane. I'm licences to operate a ships crane of up to fives tonnes capacity and it was significantly bigger than that thing.

I'd expect the RTE article is inaccurate as per the norm with journalists.

Whatever plan is place they know what they are doing.

Boaty · 31-03-2017 10:48AM

Nor is it the Ocean Challenger tug.

youtheman · 31-03-2017 11:06AM

Boaty wrote: »

The lift is outside the capacity of the 20 tonne crane of the le Granuaile
The helicopter weight is approx 5 tonnes, a quick Google tells me that the volume of the cabin of an S92 is roughly 24m3. 1m3 of water is 1 tonne, I'll let you do the math.

The salvage company will have the equipment and the knowledge to get the fuselage up safely and without destroying it.

You made a basic error in your maths. The wrecked cabin is no longer water tight, so you don't need to allow for the full volume of the cabin.

Gaoth Laidir · 31-03-2017 11:07AM

Gadgetman496 wrote: »

The Ocean Challenger made good ground overnight, she's parallel with Carna off the Connemara coast Galway.

I thought it was pretty slow actually. Last night it was already almost past Kerry so I was surprised to see it had only made that much progress this morning. Anyway, it'll get there when it gets there.

Boaty · 31-03-2017 11:18AM

youtheman wrote: »

You made a basic error in your maths. The wrecked cabin is no longer water tight, so you don't need to allow for the full volume of the cabin.

I never done out the calculations so that I couldn't be accused of getting it wrong, I was merely pointing out that 1m3 is 1 tonne. Unless you are one of the naval divers that have been at the site, you/ we have no idea what condition the helicopter is in.
For example, the helicopter might be able to hold half its cabin volume in water once it exits the sea..

Water John · 31-03-2017 11:32AM

I suspect it's not a volume alone issue that creates the extra 'weight'. It's the drag of lifting any object through water. and the displacement. A slow lift.

livedadream · 31-03-2017 11:36AM

youtheman wrote: »

Boaty wrote: »

The lift is outside the capacity of the 20 tonne crane of the le Granuaile
The helicopter weight is approx 5 tonnes, a quick Google tells me that the volume of the cabin of an S92 is roughly 24m3. 1m3 of water is 1 tonne, I'll let you do the math.

The salvage company will have the equipment and the knowledge to get the fuselage up safely and without destroying it.

You made a basic error in your maths. The wrecked cabin is no longer water tight, so you don't need to allow for the full volume of the cabin.

he didnt work it out, so how is he wrong?
and who said it is no longer water tight? only 9 men have been down there...
plus maybe three watching the RVO and that cant tell coz you know its under water and all...

31-03-2017 11:41AM

In 2014 Atlantic Towage & Marine successfully retrieved the 4 tonne keel of the yacht Rambler 100 from a depth of 75 metres off the Fastnet Rock in similar conditions to the Rescue 116 accident site at Blackrock island..

I'm sure they know they can lift the five-tonne wreckage of R116.

A 4 tonne Keel is basically a lead and steel weight, with very little resistance to water, as it is lifted and the lifting boat goes up/down with the swell.

A 5 tonne helicopter has a much larger surface area, so higher resistance to water. This will present much higher dynamic loads on the crane than a 5 tonne dead weight.

Also the bulk of the water in the helicopter will run out once it reaches the surface, so may add a tonne or so, from the flooded engine and various compartments etc.

Practical example:
Put a 2 inch hole in normal size plastic bucket, attach a rope and tow it in the water off a slow moving boat. You will be hard pushed to hold it by hand and chances are the bucket handle will break off. Note: I take no responsibility if you hurt your hand doing this.

Put a 10kg steel weight on the rope and tow it, you will have no problems holding it. Yet the 10Kg weight will be 10+ times the weight of the plastic bucket.

jmayo · 31-03-2017 11:41AM

Tabnabs wrote: »

Oh no, please report me to the internet police! :eek:

That is not a thirty tonne crane. I'm licences to operate a ships crane of up to fives tonnes capacity and it was significantly bigger than that thing.

Ehhh that's not the tug in question.
That is the Ocean Bank not the Ocean Challenger. :rolleyes:
And the Ocean Bank has a 30 tonne crane according to their website.

These guys are experts at marine salvage, the Commissioner of Irish Lights are not.
Neither for that matter are our Naval Service or the Marine Institute.
So lets bring in experts and hopefully get a speedy resolution.

These guys have worked with Marine Institute and Coast Guard in the past and at this stage would known their capabilities.

And could we have less of the mickie waving about who has or has not been on a tug or operated a crane.
I think at this stage that company have a fair idea of what they are doing.

Gadgetman496 · 31-03-2017 11:42AM

livedadream wrote: »

he didnt work it out, so how is he wrong?
and who said it is no longer water tight? only 9 men have been down there...
plus maybe three watching the RVO and that cant tell coz you know its under water and all...

One of the first pictures of the wreckage to air on TV was the large side sliding door. It most definitely is not water tight.

vicwatson · 31-03-2017 11:43AM

livedadream wrote: »

he didnt work it out, so how is he wrong?
and who said it is no longer water tight? only 9 men have been down there...
plus maybe three watching the RVO and that cant tell coz you know its under water and all...

Was cutting equipment not already used to remove the roof of the helicopter? Thought Pat McGrath said that the other day.

It's hardly still watertight also given the fact the found and removed Capt Mark Duffy from the cockpit??

http://www.thejournal.ie/rescue-116-flight-recorder-found-3305552-Mar2017/

Gadgetman496 · 31-03-2017 11:47AM

The fact that the first crew member was recovered on the surface means that crew member had to exit the craft somehow, Water tight it is not.

Gadgetman496 · 31-03-2017 11:48AM

I have not heard mention of it but it would be interesting to know if the R116 landing gear was down or not when the divers got to the wreckage.

AndyBoBandy · 31-03-2017 11:49AM

So you've all established that the crew compartment is no longer watertight, although it is most likely the largest compartment by volume, it is not the only compartment on the craft.

Gadgetman496 · 31-03-2017 11:53AM

AndyBoBandy wrote: »

So you've all established that the crew compartment is no longer watertight, although it is most likely the largest compartment by volume, it is not the only compartment on the craft.

If in fact the mention of the tail section making contact with the rock is true? I'm sure the damage would render that section susceptible to water intake too.

Cianmcliam · 31-03-2017 12:09PM

Gadgetman496 wrote: »

If in fact the mention of the tail section making contact with the rock is true? I'm sure the damage would render that section susceptible to water intake too.

I think I saw photos of at least one of the sponsons that had detached too.

Macca07 · 31-03-2017 12:11PM

Would it be possible to raise the wreckage from the ocean floor by a few feet using airbag equipment, use the Ocean Challenger to drag the wreckage away from rocks, so the Granuaile can position itself correctly above the wreckage to lift it?

Sorry if that's the understanding already, but just curious why the Ocean Challenger has been sent.

Gadgetman496 · 31-03-2017 12:29PM

Cianmcliam wrote: »

I think I saw photos of at least one of the sponsons that had detached too.

Correct.

Rescue 116 Crash at Blackrock, Co Mayo(Mod note in post 1)

Comments