September/October Issue 250: The sinking of RMS Atlantic


It was considered just a regular passage, from Liverpool to New York City. It was March, and the Atlantic Ocean could get feisty, but the ship was solid, the captain able and the trip had been done 18 times before. RMS Atlantic was only a couple years old, propelled by a state-of-the art, 600-hp compound steam engine assisted by a four-masted sailing rig. The vessel was 422 feet long, weighing 3,700 tons, and was under the command of Captain James A. Williams. A trans-Atlantic ocean liner of the White Star Line, Atlantic carried mostly immigrants between Liverpool and New York. For the first-class passengers, the ship was luxuriously appointed. But for the lower levels, the situation was progressively more crowded and crude. Steerage-level passengers were not even allowed on deck. Atlantic was built at Harland and Wolff in Belfast in 1870, the second such vessel built for the newly organized White Star Line.

On March 20, 1873, Atlantic departed Liverpool for her 19th passage to New York with 117 crew and 835 passengers, the majority of whom were in steerage. Upon encountering stormy head seas, the captain — worrying about not having enough coal to make it to New York — decided to make port in Halifax to replenish his coal stores. The night before the tragedy, Captain William’s log stated, “Sambro Island north 5º east, distance 170 miles. Ship speed varying from 8-12 knots. Wind south during the first part with rain. Veered to the westward at 8 p.m. with clear weather. At midnight judged the ship to have made 122 miles, which would place her 48 miles south of Sambro, which is located at 44º 26’ north by 66º 33’ west at the mouth of Halifax Harbor.”

On the evening of March 31 while approaching Halifax, the captain and the third officer were on the bridge until midnight during stormy conditions. Atlantic was steaming at 12 knots in low visibility and breaking seas. Due to miscalculations, Atlantic’s dead reckoning was off by 12 miles. Officers didn’t take soundings, reduce speed, post a masthead lookout or wake the captain as he requested. They did not see Sambro Island Lighthouse, which warns mariners of shoaling west of the entrance to Halifax Harbor. At 0315 LMT on April 1, Atlantic struck the rocks at Mars Head, Mars Island. All 10 lifeboats were lowered, only to be smashed or washed away. Survivors had to swim for it.

At least 535 people were lost with 371 survivors. Of the 952 aboard, 156 were women and 189 were children, all of whom perished except for one 12-year-old boy. This was the greatest loss to the White Star Line until the sinking of Titanic in 1912.

Let’s imagine the mate taking a noon meridian sight on March 27. The height of eye is 35 feet. There is no error on the sextant. He needs this sight, as the ship has been running on dead reckoning for a few days and they are approaching Halifax. We are using the 2018 Nautical Almanac. The DR is 43°15’ N by 63°10’ W. We are looking to find the calculated latitude from the mate’s lower limb observation of the sun at 1610 GMT. The Hs is 49° 28’.

A. Find the Ho.
B. What is the latitude?

A. Ho is 49° 37.7’
B. Latitude is 43° 07.4’

By Ocean Navigator