Naval News article on the ex-Kilo:
If 7 of 10 missiles were intercepted and there is no additional evidence other than one clip of
Minsk and two pictures of
Rostov then likely
two missiles hit Rostov and one hit Minsk
Explanation:
Storm Shadow has two warheads:
- precursor warhead with forward energy projection for clearing out obstacles
- main warhead with spherical energy projection for damaging the target behind obstacle
1st is like HEAT (projects forward in a straight line/cone) and is triggered by timed impact fuze.
2nd is like HE (projects spherically/mostly spherically) and is triggered by timed fuze with 1st blast as time reference.
Rostov
It is impossible for the precursor energy to take the path that Sutton indicated because the precursor energy propagates in a straight line and is sufficient to melt through the internal structure of the submarine and possibly even through the bottom of the pressure hull. There is no object inside the ship that could redirect that blast energy in that manner.
The dissipation of explosion energy is not magic but physics. It can be redirected - as thermal and pressure wave radiation - by the medium and obstacles in the blast zone. The medium in the blast zone is air. The obstacles are internal structure.
It is impossible for the main warhead energy to take that path because it is a spherical wave so it will propagate equally along 4πr2 surface. The geometry of the interior of the ship is insufficient to turn it into an explosively-formed shaped charge which would move at that particular direction and angle.
However if two impacts are assumed then the damage seen on the hull fits.
The second missile penetrates the outer hull and moves parallel to the inner hull wall which causes the blast stream to create an opening at the bottom of the hull. The main warhead explodes inside with the energy propagating spherically but since steel has good tensile (expansion) strength and inner hull has good compressive strength it means that the explosion will propagate like the air between two clapping palms. If you imagine the spherical wave as a cube for simplicity then explosion inside the outer hull will have two sides of the cube (inner and outer hull) and four sides of the cube for propagation. If there's opening in the outer hull because of the hit and the precursor those will take most of energy and will be enlarged by the blast. The image suggests the main warhead was timed very shortly after the precursor blast because most of the energy was reflected upwards.
Also the joint between the two modules may have helped to deflect blast energy. The impact point seems to be very near or exactly along it.
The first missile likely penetrates the inner hull (they're strong but not, that strong) and then the explosion directs the top half of the spherical wave to create the rip visible on the picture.
Minsk
Ropucha is an LST which is empty inside and has a light superstructure over it. When SS hit it the precursor warhead tore through the superstructure the main warhead would detonate in the cargo bay likely starting fires which weakened the structural strength of steel moving it from point of rigidity to plasticity. And because Minsk is an empty box the fires reached the external structure of the ship causing the entire superstructure to lose perimeter support and collapse on itself and then onto the cargo bay which is what the clip shows.
The door at the stern is blocking a through-deck so the ship is literally a tunnel with a superstructure over it. It was built in Gdansk in Poland so the design is well understood.
Russian shipyards have growing delays since beginning of war. "Zakladka" means keel laying, red means delay, dots mean years late.
All 636.3 which until now were coming reliably and in good order are late signifying delays. That means that dragging Rostov to Admiralty and repairing it may not be possible currently. No other shipyard is reliable as likely the entire hull will have to be tested. Rostov could in theory be repaired but the cost is likely going to be too high. The problem with submarines is that if things don't align exactly as in the project then noise is bad and noisy submarine is a useless submarine. Retesting the entire pressure hull may only take some diving depth from the ship - which could mean shallow Baltic instead of deeper Black Sea - but the rest of the mechanics and hydraulics may raise the cost to the point where building a new ship from scratch using parts from Rostov may be cheaper. Likely it will be held in the dock until options are available which blocks infrastructure and exposes ship for further attacks.
Minsk could be repaired as it is a simple ship with a simple mission profile, and the two diesel engines are likely unaffected. Shipyard space is the problem.
If I read the map correctly Sevastopol has three docks of which two (southern) are currently blocked meaning that any hull damage is a major problem.
So while Rostov is likely to be written-off (not guaranteed) parts could be re-used to build a new ImpKilo quickly, but delays in Admiralty are the main bottleneck. The yard must finish subs for Pacific and Northern fleets and fast. The Baltic and Black Sea are a conundrum but I think Black Sea will be prioritized and Baltic will have to wait a bit.