USS J McCain / Alnic MC collision near Singapore


Not saying it didn’t happen that way, it very well could have but the ships would have to be very close (similar to the video), like well under 2 cables which is way too close in an open ocean type overtaking situation. IMHO.


We are far from “open ocean” in this case when it comes to acceptable CPA’s and what type of maneuver you can get away with to safely avoid a collision without causing another close quarters situation. Now CPA’s close enough to cause hydrodynamic forces to be an issue that caused or contributed to the collision, yeah that’s too close.


Yes, we are. We are just about to enter the west-bound TSS lane of the densely trafficked Singapore Straits.

Quote from Colreg #10:
(a) This Rule applies to traffic separation schemes adopted by the Organization and does not relieve any vessel of her obligation under any other rule.

(b) A vessel using a traffic separation scheme shall:

Proceed in the appropriate traffic lane in the general direction of traffic flow for that lane.
So far as is practicable keep clear of a traffic separation line or separation zone.
Normally join or leave a traffic lane at the termination of the lane, but when joining or leaving from either side shall do so at as small an angle to the general direction of traffic flow as practicable.


As mentioned earlier, there is also the possibility that the JMC was overtaking the tanker way too close due to the traffic, and way too fast.

As the JMC passes the tanker’s bow the high pressure causes her to sheer to starboard.

Being on manual helm the QM applies port helm as she is still passing, maybe at some speed.

But as she starts to draw ahead the force disappears but she is still carrying port helm, and the high pressure from the tanker starts to act on the midships.

Bring the much smaller vessel she is most affected as not having the bulk and mass of the larger,

The waters there are about 20/25 metres deep, and have Ramunia Shoals to the W msking it a shallow water situation, magnifying the effect.

She was darkened but there was probably nothing the tanker could have done once she started the overtake.

Also, in Singapore Strait there are strong tidal streams, which add to the hydrodynamics.

There is also, for want of a better term, a king of jet wash effect from other vessels in the ame lane ofr traffic flow.

I have been Master of 20,000 tonne MPPs trading in and out of Singapore to SE Asia. There have been numerous occasions, particularly with Panamax and now post Panamax vessels, creating large areas on turbulence and instability in their wake.

The first time it happened we were half a mile behind two box boats that had overtaken us and nearly all authority of the rudder was lost. We had to go to manual and slow down, the vessel was yawing +/- 15 degrees till we got out of the wake. I believe that this is an area of fluid dynamics that warrants further investigation.

The Colregs were written in a much simpler time for ship on ship situations, not the comples scenarios we seen in Singapore and the Yellow Sea, and one questions whether they need revision or are fit for purpose.

We, as an industry, have been getting away with this for a couple of decades. Singapore used to have almost a collision a month, same in Malacca, but as the VTS has improved this has lessened.

What I fear is what happens when the big one comes along.


I’d say a typical CPA in the Singapore approach TSS is 0.5 to 0.7 mile. It’s not uncommon for ships there to be 3 or 4 cables apart on occasion.

Most ships there use a few deck lights to be better seen. A darkened ship with no AIS could certainly get missed till it was too late.


At the narrowest part the W Bound TSS off The Sisters is 4 cables wide.

Do the Math!

Yes the incident occurred in the wider approaches but having tighter constricts further in affect the behavior of vessels trading that area.

The JSM was joing a freeway of tonnage.


That’s what I was driving at. I’ve navigated this TSS and many like it. I understand that your not going to have a 5 mile CPA like your usual ocean passage but maintaining .25 miles (that’s just over a boat length for some ships) or more is more often than not doable and any closer is too close. When you get under 2 cables, especially with high speed/draft/tonnage differentials these forces are real. If the JSM experienced these forces, we agree she was too close.

In my current environment I routinely overtake and am overtaken with more excessive differentials than in this incident (speed: provided the DDG wasn’t exceeding 22 kt) with about 2 cables or so distance without much trouble, any closer your asking for trouble, unless the differential is drastically reduced.


Just making sure you guys saw this


Yes, 0624 JST, 0524 Singapore (+8)

FYI MPA Singapore are posting regular updates.

There is a radar on Horsburgh relaying into the VTS so they will have the full picture.

The light is at elevation of 31m, that puts the radar at a guess of +/- 40m

No Spin for the USN…

It is also interesting, but probably not inportant, is that the collision occurred at the reporting point for Straitrep, the Singapore VTS

If there is dense traffic you are standing VHF in hand waiting to jump in as you cross the line.

AIS has enormously helped in this area.


Just a question >>>

The McCain is not a stealth ship (…unlike the ‘Stealth Alnic MC’ tanker… managed by the ‘Stealth Maritime Corp.’ of Greece !).
However, with her never vertical superstructures, her absence of ‘inbound’ corners to act as Radar reflectors and probably Radar waves absorbing surfaces, she is optimized to return a small Radar signature.

How does she appear on a ship’s Radar screen, compared to ‘normal’ ships of similar dimensions?
Otherwise, how small a ship would she appear to be?


Just a quick Q: are USN warships on manual steering as a matter of routine? Would this include crossing a TSS?
UK merchant practice would be to adjust the auto-pilot except for large changes of direction.


AB DDG has aprox 1/50th the radar cross section of a ‘typical’ vessel her size

And yes, manually steered as a matter of routine.


Do they have and use any means of making themselves more visible on radar, such as radar reflector(s)?
Could come in handy to let others detect and plot them in traffic congested areas.


It seems like this might be good for tactical reasons as well, since the radar reflector could be stowed when they wanted to be sneaky.


I see them on my radars just fine, not sure if that’s something they can turn off or on though.


Even with heavy rain or sea clutter in use??


Latest from Straits Times:-
"Maritime and Port Authority of Singapore (MPA) said in response to queries from The Straits Times on Wednesday (Aug 23) …"

Pretty much what was evident from Vesselfinder AIS vid. Article seems ambiguous on whether JSM was undetectable by AIS and RADAR.


Typically, but I’m not looking past 10-12 miles.


I believe that the collision happened after the vessels had entered the TSS and Singapore VTS area.
It has been a while since I had to worry about reporting to VTS by myself, but as far as I can recall all vessels entering the VTS area were required to call and identify themselves with a full set of info, incl. even air draft.
Even when transiting from VTS East to VTS West reporting was required, but that may have changed now.

So my question is; does USN vessels follow such procedures, or are they exempt from even such requirements?


As I read that article, they are saying they did not see McCain on AiS (no surprise) nor on Radar, which is a bit of a surprise because (as mentioned above) there is a radar on Horsburgh lighthouse (at about 40m height) feeding the VTS (this is well within range of the collision area).