Frigate Helge Ingstad Design - Damage Survivability


#103

I find it very strange if the bilge pumps are not connected to the emergency power, also there should be bilge alarms on the bridge, and possibility to start the pumps from there, and other locations.

It’s an obligation as long as we are part of Nato, but how effective they will be in a war can be questioned after this incident. Now they present a real risk factor for people, ships and enviroment in Norway, and wherever they sail


#105

With that kind of power plant and propulsion arrangement (CODAG with twin shafts and single gas turbine), that’s probably the only feasible layout for the diesel engines, gearbox and gas turbine in a naval vessel. USCG National Security Cutter has, to my knowledge, a similar configuration - the example rendering is perhaps of that vessel.

In my opinion, the initial report from the Norwegian authorities provides a plausible explanation for the reasons leading to the sinking of the vessel after the collision: insufficient watertight integrity leading to progressive flooding of undamaged spaces. I bet everyone who has ordered naval ships in the same yard is crawling all over their engine rooms looking for similar design errors in the shaft seals and stuffing boxes.


#106

First under water pictures of the damages on NRK.no
https://www.nrk.no/hordaland/unike-undervannsbilder-viser-de-enorme-skadene-pa-knm-helge-ingstad-1.14341000


#109

dThoses inflatable (if I have it right) shaft seals seem like a good idea. The designer doesn’t have to anticipate a scenario in which they would be needed, just recognize that the openings for the shafts to pass are weak spots.

A problem with the shaft seals is one of those things that go from totally implasible to completely obvious.


#110

Working link

While I, for one, am interested in seeing photographs of the damage, they are not very useful for our speculation and analysis - all I’m seeing is twisted metal with hardly any reference points.


#111

They were lucky that nobody died. Nevertheless I think they could worked harder on saving the ship.

I still do not understand why they could not form bucket brigade for long enough just to plug that shaft seal like they did on USS Cole. The same with stuffing boxes. They got there 130 young able bodied trained men for the human bucket brigade. Did they did not have buckets on ship?

The same thing is why they would not use auxiliary electric propulsion to get the ship to nearest port.
Was the emergency power not sufficient to power the electric propulsion ?

Electric bow thruster

brunvoll-beeld-def_lr

A retractable 1MW electric bow thruster provides precise manoeuvrability when the ship is in confined areas. The bow thruster can be used as an auxiliary propulsion unit in an emergency if the main propulsion system is compromised.

PS : I heard the helicopter hangar was empty and there was no helicopter on the ship. Can someone confirm or deny this?


split this topic #112

A post was merged into an existing topic: Why did my post get deleted?


#113

Well, the divers have had a month to film the starboard propeller and the hull around it, but … there are no pictures.


split this topic #114

A post was merged into an existing topic: Why did my post get deleted?


#115

Yeah, looking like less of a good bet.

I revise it to a bet that the AIBN initial report is going to be found essentially correct.


#116

The generator room was flooded quite early apparently, thus main power supply lost. Emergency generator would most likely not be able to power the 1 mW bow thruster motor.


#117

The frigate will probably not be raised until after Christmas.

– The movements are monitored continuously. The ship is being secured both by land and underwater with remote-controlled robots. Maintenance of the straps and possible reinforcement of these straps are assessed on a continuous basis, states the Armed Forces.

–The Defence Department and the Navy are concerned that the frigate can slide into deeper water, according to Bergens Tidende.

This information is basically off topic, perhaps a new one about the raising of the HI should be started.


#118

Assuming that the shaft seals in the gear room did in fact fail there is going to be a great deal of interest as to the cause, from damage or faulty design, shipyard error or some combination.


#119

I agree. We are talking about four shaft seals installed 10 years ago. I must say I don’t know how to test such seals. Are they Class items or Solas items or just Owner’s own responsibility under some planned maintenance system? Answer is simple! There are four sister ships! What do they do there?


#120

They have reportedly installed inflatable bellows as an interim measure on the sister ships.


#121

A non-contacting bulkhead shaft seal with a hydro active seal seems to be the answer. Was it too expensive or not yet on the market at the time of the design or building of the frigates?

From what I understand this product was originally designed for the US Navy and later a commercial grade bulkhead shaft seal was introduced.


#122

Well, it would be much better to make the shaft tunnels between the aft generator room and the gear room through the aft engine room watertight. But maybe nobody cared about it? I wonder what the sister ships look like? It doesn’t look good for KNM.


#123

“I videoene kan man for første gang se nærbilder av skadeomfanget på KNM «Helge Ingstad». I kollisjonen ble lager og lugarer akterut, akter generatorrom, aktre maskinrom, girrom og forre maskinrom truffet av ankeret på tankskipet. Alle rommene fikk vannfylling.”

Well, it seems the video only shows structural damages to the superstructure and deck house high above waterline, which are built in 6 or 4 mm plates, which have been ripped away. Ships do not float on superstructures and deck houses.
It is interesting to note that it took the shipyard one year to build the hull, superstructure and deck house. Then the ship was launched and spent another two years alongside for outfitting. Maybe they forgot to close the openings and fit stuffing boxes in the bulkheads during outfitting?


#124

I have been involved with a number of civil engineering jobs as a contractor. In every case the client had a resident engineer on site at all time who had responsibility to check the work we did was in accordance with the contract spec. After he signed it off… it was down to him.

I would have thought a similar arrangement would be in place for building a new ship. In which case either the navy didn’t specify sealed prop tubes, or they did but didn’t check the build was in accordance withnthe spec.

By way of contrast, there was a recent program about the RN’s new flat top. Billions of pounds worth of ship bought to a vibrating halt because someone didn’t fit a seal peoperly.


#125

Maybe survivability is no longer a navy concern. The navy knows that the ship will be destroyed by the first accurate incoming missle. The life expectancy of these fast light ships in a serious conflict is probably only a few minutes. This is why I say the Navy should build a large number of cheap basic ships, not a handful of billion dollar science fiction ships.