In 1980/81 the Austin & Pickersgill shipyard in Sunderland built three SD-18 general cargo ships for the Pakistan National Shipping Company in Karachi. The ship type was a further development of the extremely successful Liberty replacement ship type SD-14 . Against the background of the changed market conditions in the course of global containerization , the shipyard was unable to sell any further units of the type. All three ships remained in the possession of the Pakistan National Shipping Company for their entire service life. The Murree sank in 1989 in bad weather as a result of the container cargo slipping in the English Channel, the other two ships, Kaghan and Ayubia , were broken up in Gadani Beach in 2001 and 2004.
The SD-18 ships had superstructures arranged aft above the machinery and four cargo holds with a volume of 24,345 m³ (bulk goods). The forward cargo hold had a hatch with McGregor single-pull hatch covers , the rear three holds had double hatches , which were also closed with McGregor single-pull hatch covers. Six cargo booms were available as their own loading gear, two with a 35-ton capacity and four with 25 tons each.
A six-cylinder, two-stroke Sulzer RND68M diesel engine, manufactured under a Sulzer license by Hawthorn-Clark, Newcastle, served as the drive and acted directly on the fixed pitch propeller. The engine had an output of 8700 kilowatts and allowed a speed of 15.2 knots. At the end of the 1980s, the Ayubia received a new engine of the same type, which had been built by Hitchi Zosen. The on-board energy was provided by three auxiliary diesels with 450 kVA each. A bow thruster was not available.
