Science Spin May 2007

Mapping shipwrecks in Irish waters

By Sean Duke

Ireland might be a small country, but its offshore area certainly isn't. The massive Irish offshore area of 850,000 square km reaches out towards Iceland, North America and the Iberian peninsula. This watery realm has devoured many vessels and seafarers. Until recently, much of the hard data on shipwrecks lying in Irish waters was fragmented and very confused. However, a project to survey shipwrecks in Irish waters by combining all the known information, and generating new data along the way has proven extremely successful.

The shipwreck project supported by the Geological Survey of Ireland (GSI) and the National Monuments Service (NMS) was completed at the end of 2006. It used the latest seafloor imaging techniques to produce spectacular 3-D images of famous wrecks such as the Lusitania -- as they appear today on the seabed. The project managed to increase the number of shipwreck records, from 140 when it began, to 246 when it was completed. Many of these new records correspond to 'new shipwrecks' previously unknown. In time, their identity could now be revealed either by divers, or robotic submersibles.

Dr Stuart Bennett, a TCD geologist and one of the lead researchers on the project said that the inclusion of 71 'new wrecks' in the database is quite exciting. These lie outside any of the known wreck positions so there was no record of their existence.
Funding from the NMS through its underwater archaeology unit supported the work of Dr Stuart Bennett who worked on the wreck survey between April and November 2006 before returning to TCD.

The survey was the brainchild of Dr Eibhlin Doyle of the GSI, and Fionbarr Moore and Karl Brady of the NMS, who all had seen the logic of bringing together all existing records into a single wreck database which could then be published.

Background

The first attempt to survey and map the Irish offshore area -- since the days of the British Admiralty charts -- came with the establishment of the Irish National Seabed Survey, or INSS. In 1999 the government provided €33 million to set up the INSS with the goal of surveying and mapping Irish waters. Its work was completed at the end of 2005.

The work began in 2000, and was managed by the GSI and the Marine Institute. First to be surveyed were the deep waters, with depths defined as greater than 200 metres. Here survey technologies called multi-beam, sub-bottom, gravity and magnetics were used.

The deep water work was completed in 2002. The next job was to survey waters less than 200 metres in depth, and Marine Institute research vessels were used for this purpose. There were a number of bays surveyed by the INSS team such as Clew Bay, Mulroy Bay and Killala Bay, using airborne laser surveys, commonly known to geologists as LIDAR.

In the process of the INSS work mapping the Irish seabed many features were observed, including submarine slides, mound features, deep canyons, ice marks and shipwrecks. Some of the shipwrecks observed by the INSS were later on found to be 'new' wrecks.

The INSS has been succeeded by a new project called the Integrated Mapping for the Sustainable Development of Ireland's Marine Resources, or INFOMAR, which has continued where the first project left off. The goal of INFOMAR, which has funding up to 2013, and again is managed by the GSI and Marine Institute, is to complete the mapping of the Irish offshore, including the near shore areas, and all of the bays.

Interest

There is a great deal of interest in shipwrecks from divers, and the general public. The tale is dramatic, recounting a desperate, life-and-death struggle that took place in Irish waters over two World Wars involving German U-Boats and the British Navy. Older boats sank too, of course, just think of the Spanish Armada, but these boats were made of wood and, thus, very little is likely to remain on the seabed from such earlier times. The oldest known shipwreck in Irish waters is the Queen Victoria, which sank in a storm off Howth in 1853. This was a wooden vessel, and all that is left of it now are its metal boilers.

The project to survey shipwrecks, name and locate them is not exclusively of interest to divers, who can be fanatical in their enthusiasm for wrecks, and members of the public with an interest in naval history. Others are interested too, for example, fishermen. Shipwrecks provide a hazard for fishing vessels whose nets can get caught in them, so the fishing community would like to know precisely where all the wrecks are located. For marine biologists, meanwhile, wreck data provides an opportunity to study the unique micro-habitats that exist around wrecks, while marine geologists can learn more about sub-sea sedimentary processes, by looking at how sediments behave around the wrecks.

There is talk of producing a publication that would satiate all this widespread interest in wrecks in Irish waters. Each page would contain the name of a wreck, an image of what the boat looked like before it sank, what it looks like now on the seafloor -- if such an image is available -- information on how it sank, and a map to indicate its exact location.

Datasets

Shipwrecks were identified and catalogued under INSS, and this will now continued under INFOMAR. So this dataset is likely to continue to grow in the coming years.

This is not the only dataset in town, however, far from it. Since 1997, the NMS has been compiling its own inventory of shipwrecks lying in Irish waters. This inventory includes all wrecks up to and including 1945, and there are about 10,000 records in the database at this stage. The NMS database was compiled from a number of sources including Lloyd's List, British parliamentary records, newspaper records, books and specialist websites that have information from divers such as www.irishwrecksonline.net and www.uboat.net.

There are other data sets that are worthy of integration with the rest, including those from the Coastal and Marine Resource Centre in Cork, the Petroleum Affairs Division (PAD) of the Department of Communication, Marine and Natural Resources. The UK Hydrographic Office (UKHO) is another very useful database as it contains information on wrecks in Irish waters such as the vessel name, its dimensions and the circumstances of its loss.

The Lusitania

This 'protected' shipwreck is the most famous one lying in Irish waters. The huge steam passenger liner, which was sunk off Cobh, was attacked by a German U-20 submarine in 1915. Conspiracy theories abound about the sinking of the Lusitania, which is not surprising, as this was a key turning point in World War I prompting as it did the US decision to enter the war on the Allied side. The boat was en route from New York to Liverpool and approximately 1,200 lives were lost after it sank following a torpedo hitting its starboard side. According to divers, the wreck is a mess on the seabed, lying on its starboard side, with its different floors having slid past each other.

The Leinster

This was a Royal Mail ship, built in Birkenhead in 1896. It was torpedoed and sunk about 25 km east of Dublin when it was crossing the Irish Sea between Dublin and Holyhead. This sinking is regarded as Ireland's worst maritime disaster. The ship was torpedoed a number of times and there was an attempt to tow it back to Dublin. British navy ships set sail from Dublin to rescue it, but the Germans got wind of this and torpedoed it again. It sank not far east of Dublin, where it now lies between sandbanks, and broken mid ships.

The Queen Victoria

This is the oldest known wreck named in the database. It was a wooden, paddle steam ship, built in 1837, that sank in a snow storm off Howth Head in 1853. The ship was travelling from Liverpool to Dublin when the storm hit off Howth, and it sank close to the lighthouse there. There were 112 people, plus general cargo on board, and 40 people survived. Today, given that this was a wooden ship, there is little by way of the shape of a ship on the seafloor. According to divers, the metal boilers are the most prominent remnants that remain at the wreck site, and these are still standing tall on the seafloor.

The Curacoa

In 1942, at the height of World War II, the Curacoa was in a convoy escorting the Queen Mary when a decision was made onboard to chase a u-boat that had apparently been sighted nearby. Unfortunately, for all aboard the Curacoa, it crossed the path of the Queen Mary in its pursuit of the u-boat and was promptly cut in two in a resulting collision, and sunk. The Queen Mary did not attempt to stop and rescue survivors from the Curacoa. She was too busy trying to survive a potential u-boat attack by engaging in zigzag avoiding manoeuvres. The Curacoa lies northwest of Bloody Foreland, Donegal. The two parts of the ship lie on the seafloor about 500 metres apart from each other.

The Athenia

The first civilian casualties of World War II were lost, not in Poland, but about 380 km to the west of the west of Ireland coastline when the Athenia, a larger passenger liner was sunk. The sinking occurred on the 3rd September 1939 just as England and France were declaring war on Germany. The Athenia was mistaken for an armed merchant cruiser, torpedoed by U-30 and sunk. A lot of people were rescued in this event. The boat lies in deep waters so it is harder to image than with wrecks lying in shallower waters.

The Empire Heritage

This vessel was torpedoed and sunk by a U-Boat, which may have been operating as part of a 'wolf pack' of submarines, off the northwest coast. Another boat in the area, the Pinto went to rescue the survivors, but it too was sunk by a U-Boat. The Empire Heritage, was carrying a cargo of tanks, and the tanks have been seen by divers dramatically littered across the seabed. Multibeam data picked up the presence of some of the tanks.

German U-Boats

Ireland may have been neutral, but its offshore was the scene of a life-and-death struggle between German U-Boats and the British Navy. Who eventually won that struggle is testified by the fact that there are up to 40 submarines recorded at the bottom of Irish waters. Off the north coast, there is a cluster of U-Boats that are the result of Operation Deadlight at the end of the war. This operation, carried out by the British Navy, involved the deliberate scuttling of seized U-Boats. The submarines were towed out to sea, towards a designated area, but some broke their lines and had to be shelled and sunk closer to shore than was planned. The U-Boats are quite obvious when seen with multibeam data on the seafloor, given their long and narrow shape.