micfradus wrote:
Slightly off topic.
The ton class; recent picture of SAS Durban has made me wonder how many are floating still.
Museaum ship, laid up, mothballed. not sure the correct term.
From the two pictures ive found of Durban, she doesnt look like she has mooved in a long time.
From what ive found on the US laid up vessels, they seem to be on a floating barch.
I am only wondering because, like the purchase of the A109, and now looking to redifine their role, will the new OPV really be able to carry out the duties of MCM, or will SAN need a designated MCM.
I know technoligy allows uav and other new things. But incase, are they current riverclass able to be mothballed too.
I mean, I read that Protea still has many years of service left in her. I understand that wood rots, but why would a Navy allow it (Durban) rot away?
To me, It would be better served to donate these vessels to a Coast guard unit rather than letting them die. That includes the river class once biro comes into effect.
The SAS Durban was stricken from navy charge many, many years ago - the South African Navy no longer has any rights over or responsibilities towards her. He current owners do.
Mine countermeasures, broadly, fall into two sections - contact mines and influence mines.
Contact mines are difficult for whoever wishes to lay them. The bit with horns that bobs about in the movies is only half of a contact mine. A fairly substantial vessel, fitted with minelaying rails, is needed. South Africa's best defence is to identify such vessels and prevent them closing to areas where minelaying is possible. Failing that any stern trawler makes an excellent minesweeper - it already has onboard a powerful winch, it's crew is adept at handling otterboards and the extra sweep gear can be fitted rapidly should it ever become necessary.
Influence mines are also a problem - much easier to lay and air-droppable but the South African coast affords few places where they can be laid. Modern influence mines have things such as ship count, ship identity, multiple sensors and some even dig themselves into the sandy bottom. The old jackhammer in a barrel (acoustic mines) or electro-magnetic pulses no longer work with them. In fact by the end of WW2 they were no longer working. The modern mine ignores all the old traditional methods of sweeping. It is sensitive enough to explode only when "worthwhile" targets go over it.
Defence against influence mines consists of identifying the mine. Today's minehunting sonar with all it's ancillary gear will fit in the boot of your car. In fact the T-craft did a lot of test runs with such multi-frequency minehunting sonars. They can be towed at a fairly high speed and will identify individual rivets on a mine (in the unlikely even the mine should have rivets). A mini-PAP is not much bigger than a 30cm torpedo - it is capable of going down to the mine, using TV cameras to give the ships a positive ID and place an explosive charge on the mine. This charge, fired either by remote control or timer will neutralize the mine. If push comes to shove a diver can replace the PAP.
It is a little outre to have a ship dedicated just to mine countermeasures these days. The minesweeper - once all those still currently in service worldwide are scrapped - will probably not be replaced. OPVs and IPVs will take on this function.
What has made the revolution in minehunting sonars possible in the last decade is oodles of processing power which was not available before. A modern multi-frequency sonar - the one I am familiar with - will use up to 90 gigabytes a second. It gives a "picture" of the seabed that is almost as if a close-up camera took it. One defence, and one the navy has had the facilities for for the last 6 or seven years, is to do regular scans of likely places - like harbours - on a daily (or more often) basis. The computers instantly then pick up anomalies comparing the most recent scan with previous ones - and these can then be treated as mines until shown to be otherwise. The system was extensively used in our harbours during the FIFA world cup. The whole box-and-dice fits in a small motorboat (even smaller than a Namacurra).
As to the Protea - she is old. I saw her arrive, brand new, as a raw recruit. I should be on the scrap heap - let alone her! She has had major rebuilds - her engines were replaced some time back with MTUs - but ships are complex things and the older they are the more often small annoying things break down. Valves fail to work, pipes fail, etc.etc. A refit that would replace all the functioning items would cost more than a new ship. So why indulge - buy a new ship!
Login
Register
FAQ
Search
Pity about those that were cut up and scrapped. Also looks like you've had a lot less wind in Hout Bay as well.