Hangor On

Forty five years (and two days) ago a part of a naval war led to the first sinking of a ship by submarine since the Second World War, one of only three to date. The other two being the ARA Belgrano sunk by HMS Conqueror and the sinking of the ROKS Cheonan.
The subject for today's article was the sinking of the INS Khukri in 1971. A subject I was hesitant to look at, as the last time I featured an India-Pakistan war story I had to wade through such a mountain of bile, nationalism and propaganda it put me right off. Luckily this time saner heads have prevailed and the incident is discussed in a much more educated fashion. However I mention the above so that you can understand when I give a warning about the authenticity of some of the data in this article. Some of it comes from eye witness accounts, and thus may well have been edited by the various sides. To cap it all there is still some controversy on the subject.

The 1971 Indo-Pakistani war lasted just thirteen days, and the Pakistanis came off the worst and lost. The war overall was a part of the complex and unpleasant Bangladeshi Liberation War. At the start of the war the Pakistani Navy was blind and had no intelligence on what was happening at sea, and so its submarine, PNS Hangor (of French origin and built in 1968), sailed out into the Indian Ocean to see what intelligence could be found.

The PNS Hangor

She found information all right. The PNS Hangor detected a large fleet of Indian ships closing to create a blockade and bombard the main Pakistani Navy port of Karachi. PNS Hangor transmitted this warning to the Pakistani Navy, but for some unknown reason the warning wasn't acted upon by the PNS Hangor’s superiors. The message was also picked up by the Indians and they did act on it. They dispatched a number of maritime patrol planes and Sea King helicopters to search for this submarine. Along with the air assets a trio of British built Blackwood frigates were also dispatched. However one was in port with boiler trouble, and that just left two ships, the INS Khukri and INS Kirpan.

INS Khukri

The INS wasn't the only navy to be suffering mechanical troubles. The PNS Hangor had also developed an engine fault which reduced its speed. So when she came to periscope depth briefly sometime after 1100 on the 9th of December 1971, she could see the two Indian ships but lacked the speed to approach them to make an attack. However Commander Ahmed Tasnim, the captain of the PNS Hangor, could see the ships were conducting a search pattern. Both navies had the same background, and used the same text books and publications, so Cmdr Tasnim was able to recognize the pattern the Indians were using and decided to position himself ahead of the ships to launch his attack. However there was a complication. During the day a pair of Sea Kings started to operate in his area with dipping sonars. These would have picked up the sub moving to its ambush position. However at about 1700 to 1800 both Sea Kings left the search area. The Indian vessels were informed that their relief would be with them in an hour, but the replacements never showed up. This let the PNS Hangor take up its ambush position. Now at 40m depth the two Indian frigates were on a closing course moving at just 12 knots to improve the performance of their sonar, both of them were zig-zagging. Unable to pick up his targets in the dark, at a range of 9800m Cmdr Tasnim decided to dive to 55m and use sonar to make his attack. At 1957 he fired his first homing torpedo.

Cmdr Tasnim is pictured in the insert

Each torpedo had a travel time of about five minutes. The first torpedo missed, so a second one was launched. It hit the INS Khukri in the engine room, instantly destroying all power and causing severe flooding. On the bridge of the INS Khukri the captain was thrown from his chair and smashed his head on the bulkhead, opening a severe wound. Despite this he immediately ordered full speed, but his ship was already doomed. The captain sent one of his officers to assess the situation whilst he tried to regain control of his ship. The officer returned almost immediately suggesting that the order to abandon ship was to be given as the rear of the ship was already under water. The captain agreed. However there was only a single escape path. As the ship was at general quarters only a few stairwells were undogged. The rear one was underwater, so that left the one leading to the bridge. The captain and two of his officers remained pulling men out of the stairwell and sending them overboard until the bridge was nearly at the waterline, the captain then pushed the two remaining officers into the water and returned to rescue more men. Captain Mahendra Nath Mulla went down with his ship aged 45, along with nearly 200 others.

Captain Mahendra Nath Mulla

The other ship (INS Kirpan) turned to attack the PNS Hangor with depth charges. However the PNS Hangor fired again and hit the Kirpan and damaged her. The Hangor then started to retreat out to deeper waters. The INS Kirpan also left the area, and here is where the modern controversy lies. Many claim she should have stayed on station to rescue the survivors of the INS Khukri. The Indian Navy launched Operation Falcon over the next four days to try and sink the PNS Hangor. However as the PNS Hangor had headed out to deeper waters, and not directly towards her home base at Karachi she survived. Despite this the PNS Hangor recorded 36 depth charge attacks over the next four days, one salvo bracketed the submarine and left the crew tensed for the killing blow which never came.
The PNS Hangor remained in service until 2006 when she was decommissioned, before becoming a museum ship at the Pakistan Maritime Museum. The last officer to inspect her was Vice Admiral Ahmad Tasnim.

PNS Hangor at the Pakistan Maritime Museum

Image credits:
urbanpk.com and www.shipspotting.com