When Richard Montgomery arrived off
Southend, she came under the authority of the Thames naval control at
HMS Leigh located at the end of
Southend Pier. The
harbourmaster, responsible for all shipping movements in the
estuary, ordered the ship to a berth off the north edge of
Sheerness middle sands, an area designated as the Great Nore Anchorage.
On 20 August 1944 she dragged anchor and ran aground on a sandbank around 250 m (820 ft) from the
Medway Approach Channel, in a depth of 24 ft (7.3 m) of water. The general dry cargo liberty ship had an average draft of 28 ft (8.5 m), but Richard Montgomery was trimmed to a draft of 31 ft (9.4 m). As the tide went down, the ship broke her back on sand banks near the
Isle of Sheppey about 1.5 mi (2.4 km) from Sheerness and 5 mi (8.0 km) from
Southend.
A
Rochester-based
stevedore company was given the job of removing the cargo, which began on 23 August 1944, using the ship's own cargo handling equipment. By the next day, the ship's hull had cracked open, causing several cargo holds at the bow end to flood. The salvage operation continued until 25 September, when the ship was finally abandoned before all the cargo had been recovered. Subsequently the vessel broke into two separate parts, roughly amidships.
During the enquiry following the shipwreck it was revealed that several ships moored nearby had noticed Richard Montgomery drifting towards the sandbank. They had attempted to signal an alert by sounding their sirens, but without avail because Captain Wilkie of Richard Montgomery was asleep. The ship's chief officer was unable to explain why he had not alerted the captain. A board of inquiry concluded that the anchorage the harbour master assigned had placed the ship in jeopardy, and returned the captain of Richard Montgomery to full duty within a week.