SS Richard Montgomery

SS Richard Montgomery was an American Liberty cargo ship built during World War II. She was named after Richard Montgomery, an Irish officer who fought in the American Revolutionary War.[4]

Thames Richard Montgomery KC 7722 (Modified) (cropped).JPG
Visible masts of the wreck of Richard Montgomery
United States
NameRichard Montgomery
NamesakeRichard Montgomery
OwnerWar Shipping Administration (WSA)
OperatorAgwilines Inc.
Orderedas type (EC2-S-C1) hull, MC hull 1199
BuilderSt. Johns River Shipbuilding Company, Jacksonville, Florida[2]
Yard number7
Way number1
Laid down15 March 1943
Launched15 June 1943
Sponsored byMrs. Rockwell
Completed29 July 1943
FateGrounded on 20 August 1944 then broke in half and sank on 25 August
General characteristics [3]
Class and type
  • 441 feet 6 inches (135 m) oa
  • 416 feet (127 m) pp
  • 427 feet (130 m) lwl
Beam57 feet (17 m)
Draft27 ft 9.25 in (8.4646 m)
Installed power
  • 2 × Oil fired 450 °F (232 °C) boilers, operating at 220 psi (1,500 kPa)
  • 2,500 hp (1,900 kW)
Speed11.5 knots (21.3 km/h; 13.2 mph)
  • 562,608 cubic feet (15,931 m3) (grain)
  • 499,573 cubic feet (14,146 m3) (bale)

The ship was wrecked on the Nore sandbank in the Thames Estuary, near Sheerness, Kent, England, in August 1944, while carrying a cargo of munitions. About 1,400 tonnes (1,500 short tons) of explosives remaining on board presents a hazard but the likelihood of explosion is claimed to be remote.[5]: 2000 survey, p21–22 [6][7]


Richard Montgomery was laid down on 15 March 1943 under a Maritime Commission (MARCOM) contract, MC hull 1199, by the St. Johns River Shipbuilding Company, Jacksonville, Florida. She was sponsored by Mrs. Rockwell, the wife of the director of MARCOM, Production Division, and was launched on 15 June 1943. She was the seventh of the 82 liberty ships built by the yard.[2][1]

Service historyEdit

She was allocated to Agwilines Inc. on 29 July 1943. In August 1944, on what was to be her final voyage, the ship left Hog Island, Philadelphia, where she had been loaded with 6,127 tons of munitions.[citation needed]

She travelled from the Delaware River to the Thames Estuary, then anchored while awaiting the formation of a convoy to travel to Cherbourg, France, which had come under Allied control on 27 July 1944, during the Battle of Normandy.

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.[8]

On 20 August 1944 she dragged anchor and ran aground on a sandbank around 250 m (820 ft) from the Medway Approach Channel,[9] 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.[7]

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.[10]

Status and riskEdit

Map of the Thames Estuary with the exclusion zone around the wreck of Richard Montgomery, and locations of proposed airports: 1. Cliffe; 2. Grain (Thames Hub); 3. Foulness; 4. Off the Isle of Sheppey; 5. Shivering Sands ("Boris Island").
Warning buoy marking the wreck of SS Richard Montgomery (masts visible to left)

According to a 2008 survey, the wreck is at a depth of 15 m (49 ft), on average, and leaning to starboard. At all states of the tide, her three masts are visible above the water.[5]: 2008 survey 

Because of the presence of the large quantity of unexploded ordnance, the ship is monitored by the Maritime and Coastguard Agency and is clearly marked on the relevant Admiralty charts. In 1973, she became the first wreck designated as dangerous under section 2 of the Protection of Wrecks Act 1973. There is an exclusion zone around her monitored visually and by radar.[a] The exclusion zone around the wreck is defined by the following co-ordinates:

Map this section's coordinates using: OpenStreetMap 
Download coordinates as: KML

According to a survey conducted in 2000 by the Maritime and Coastguard Agency,[5]: 2000 survey, p21–22  the wreck still held munitions containing approximately 1,400 tonnes (1,500 short tons) of TNT high explosive.[5]: 2000 survey, p21–22  This comprises the following items of ordnance:

An investigation by New Scientist magazine in 2004, based partly on government documents released in 2004, concluded that the cargo was still deadly, and could be detonated by a collision, an attack, or even shifting of the cargo in the tide. The deterioration of the bombs is so severe that they could explode spontaneously.[12] Documents declassified shortly before revealed that the wreck was not dealt with immediately after it happened, or in the intervening 60 years, due to the expense.[12]

The Maritime and Coastguard Agency nevertheless believes that the risk of a major explosion is remote.[13] The UK government's Receiver of Wreck commissioned a risk assessment in 1999, but this risk assessment has not been published.[12] The Maritime and Coastguard Agency convened with local and port authorities to discuss the report in 2001 and concluded that "doing nothing [was] not an option for much longer".

One of the reasons that the explosives have not been removed was the unfortunate outcome of a similar operation in July 1967, to neutralize the contents of the Polish cargo ship Kielce, that sank in 1946, off Folkestone in the English Channel. During preliminary work, Kielce exploded with a force equivalent to an earthquake measuring 4.5 on the Richter scale, digging a 20-foot-deep (6 m) crater in the seabed and bringing "panic and chaos" to Folkestone, although there were no injuries.[5]: 2000 survey, p21–22  Kielce was at least 3 or 4 miles (4.8 or 6.4 km) from land, sunk in deeper water than Richard Montgomery, and had "just a fraction" of the load of explosives.[10]

According to a BBC News report in 1970,[14] it was determined that if the wreck of Richard Montgomery exploded, it would throw a 300 metre (1,000 feet)-wide column of water and debris nearly 3,000 metres (10,000 feet) into the air and generate a wave 5 metres (16 feet) high. Almost every window in Sheerness (population circa 20,000) would be broken and buildings would be damaged by the blast. However, news reports in May 2012, including one by BBC Kent, stated that the wave could be about one metre (3 feet) high, which although lower than previous estimates would be enough to cause flooding in some coastal settlements.[15][b]

When the condition of the munitions was originally assessed there was concern that copper azide, an extremely sensitive explosive, would be produced through reaction between lead azide and copper from fuse components (lead azide would react with water vapour, rather than liquid water, to form hydrazoic acid, which could react with copper in the detonating cap to form copper azide).

The Maritime and Coastguard Agency (MCA) said in 1998, "as the fuses will probably all have been flooded for many years and the sensitive compounds referred to are all soluble in water this is no longer considered to be a significant hazard".[5]: 1997 survey 

Critics of government assurances that the likelihood of a major explosion is remote argue that one of the fuses of the 2,600 fused-fragmentation devices could become partially flooded and undergo the reaction producing copper azide.[12] A knock, such as caused by the ship breaking up further, or a collision on the busy shipping lane, could cause the copper azide to explode and trigger an explosive chain reaction detonating the bulk of the munitions.

The wreck site has been surveyed regularly since 1965 to determine the stability of the structure, with a diver survey being completed in 2003.[5]: 2003 survey  High-resolution multi-beam sonar surveys in 2005 and September 2006 found that there had been no recent significant movement of the wreck.

Surveys undertaken in 2008 and 2009 by the MCA, showed that the ship was continuing to deteriorate structurally, with accelerated deterioration in some areas and new cracks appearing in the bow section of the wreck.[17] The report states that "Whilst significant structural collapse does not appear to be imminent, surveys suggest that this prospect is getting closer."[5]: 2008 & 2009 surveys  The increasing calls for a new airport in the Thames estuary would mean a solution would have to be found for removing the wreck, or at least making it safe, should the airport be built.[18]

The 2010 survey report,[5]: 2010 survey, s5  released in May 2012, found that, while there had been little change in 2009–2010, the future was uncertain due to the "dynamic nature" of the surrounding environment.[19] Mayor of London Boris Johnson said that engineers had found the wreck would not prevent construction of an airport, and the wreck area would have to be considered.[19] Julian Huppert, the co-chair of the Liberal Democrats committee on transport, disagreed, saying: "This report shows the ship's slow deterioration is continuing with the lethal cargo still on board", and "This must surely put an end to the bonkers idea of building an airport in the Thames estuary."[19] A 2013 Daily Telegraph article quoting local historian Colin Harvey, agreed the ship would have to be removed before any airport was built and printed a spectrogram showing the ship clearly broken into two pieces.[20] However, a DfT spokesperson said that the ship remained stable, and the likelihood of an explosion was remote; the matter of the ship was unrelated to the ongoing development of the aviation strategy.[19]

In June 2020, the DfT announced it was looking for a contractor to remove the ship's three masts as they were placing undue strain on the rest of the vessel structure.[21] The Ministry of Defence (MoD) warned that the collapse of a mast could detonate ordnance, and Royal Navy specialists would need to remove them safely. In December 2021 it was reported that a contractor supported by the Navy would remove the ship's masts, starting in June 2022.[22][23][24]

In mediaEdit

In the second series of the Sky programme COBRA, broadcast in 2021, the Montgomery (unnamed in the series) explodes as a consequence of undersea earthquakes, with the consequences predicted in the 1970 BBC report: heavy flooding, property damage and great loss of life (including the local MP) in Sheerness.

See alsoEdit


  1. ^ Currently the only other similarly designated wreck is that of SS Castilian, which sank off Holyhead in 1943, whilst en route to Lisbon, and was designated in 1997, as a result of diver interference with her cargo of munitions.[11]
  2. ^ Staff at BBC Kent quoted Liberal Democrat Julian Huppert that "[an explosion] would blow out every window in Sheerness, and create a 16ft wave just outside the capital", but went on to state lower down that article that "Previously experts have said if the wreck exploded it would cause a metre-high tidal wave"[16]


  1. ^ a b c MARCOM.
  2. ^ a b St. John's River SBC 2010.
  3. ^ Davies 2004, p. 23.
  4. ^ MARAD.
  5. ^ a b c d e f g h i "The SS Richard Montgomery: Information and survey reports". UK Government. 8 June 2020. Links to background information and surveys. Updated when necessary.
  6. ^ "SS Richard Montgomery wreck 'bomb risk' to estuary airport". BBC News. 30 May 2012. Archived from the original on 19 August 2012. Retrieved 31 August 2012.
  7. ^ a b Sawyer, L. A.; Mitchell, W. H. (1985). The Liberty Ships: The History of the "Emergency" Type Cargo Ships Constructed in the United States During the Second World War (Second ed.). London: Lloyd's of London Press Ltd. pp. 159–160. ISBN 1-85044-049-2.
  8. ^ River Thames Sea Reach (Map) (4 February 1972 ed.). Admiralty Hydrographic Office, London.
  9. ^ "Maritime and Coastguard Agency". Archived from the original on 7 September 2011. Retrieved 8 September 2011.
  10. ^ a b Skinner, Nicholas (2011–2016). "The Ticking Timebomb". Southend Timeline. Retrieved 17 May 2017.
  11. ^ "Receiver of Wreck Annual Report 2003" (PDF). The Maritime and Coastguard Agency. Archived from the original (PDF) on 27 September 2007. Retrieved 29 October 2006.
  12. ^ a b c d Hamer, Mick (21 August 2004). "The doomsday wreck". New Scientist: 36–39. Z. Archived from the original on 24 April 2015. Retrieved 11 September 2017.
  13. ^ "SS Richard Montgomery web page". The Maritime and Coastguard Agency. Archived from the original on 1 April 2011. Retrieved 29 October 2006.
  14. ^ "Wrecked warship [incorrect: is a cargo ship] is a 'timebomb'". BBC News. 19 August 2004. Archived from the original on 17 June 2006. Retrieved 29 October 2006.
  15. ^ Cecil, Nicholas (30 May 2012). "Timebomb ticking in Thames Estuary could put Boris Island plans in jeopardy". London Evening Standard.
  16. ^ BBC Kent staff (30 May 2012). "SS Richard Montgomery wreck 'bomb risk' to estuary airport". BBC Kent. Archived from the original on 24 November 2018. Retrieved 20 June 2018.
  17. ^ "SS Richard Montgomery structural collapse 'getting closer'". BBC News Online. 6 September 2011. Archived from the original on 20 January 2012. Retrieved 7 September 2011.
  18. ^ Gourlay, Chris (18 October 2009). "HeathrowonSea travel hub inches towards Heathrow airport". The Times. London. Archived from the original on 12 June 2011. Retrieved 23 May 2010.
  19. ^ a b c d Cox, Marijke (22 June 2012). "Building an estuary airport close to sunken warship [incorrect: is a cargo ship] branded "bonkers"". Kent News. Archived from the original on 3 December 2016. Retrieved 13 February 2018.
  20. ^ "Boris Island airport site 'could blow up at any minute'". 24 January 2013. Archived from the original on 13 February 2018.
  21. ^ "Masts to be cut from Thames Estuary wreck packed with explosives". BBC News. 4 June 2020.
  22. ^ Nicholls, Dominic (29 December 2021). "Sunken warship [incorrect: is a cargo ship] in River Thames with explosives on board could cause 'mass damage and loss of life'". The Telegraph. Archived from the original on 12 January 2022.
  23. ^ "Navy to dismantle sunken cargo ship on Thames holding unstable explosives". the Guardian. 30 December 2021. Retrieved 31 December 2021.
  24. ^ Kent Online: Work starts on making Sheppey bomb ship Richard Montgomery 'safe'. By Claire McWethy, Published: 15:04, 20 October 2021. Updated: 03:45, 21 October 2021. Accessed 13 February 2022.


External linksEdit

Coordinates: 51°27′57″N 0°47′12″E / 51.46583°N 0.78667°E / 51.46583; 0.78667