Eerie Port

Eerie Port, on the northwest shore of the Great Cumbrae in the Firth of Clyde, was the site of one of the more unusual installations to form part of the Clyde's submarine defences during World War II, an acoustic listening post which listened to the underwater sounds in the approaches to the firth.

Listening post

The post was located in two single storey buildings near shore, one of which housed equipment intended to listen for, and detect the sound of any vessels attempting to penetrate the Cloch boom which stretched from Dunoon to Cloch Point, and protected the approach to the Firth of Clyde. Although not further described, the station must have been connected to an array of hydrophones (underwater microphones) which fed what appears to have been a huge, valve-based amplification system. Transistors were not invented until 1947, well after the war, and the equipment block has been described as having large ventilators, consistent with the need to dissipate significant amounts of waste heat, as would have been produced by an installation which utilised a large numbers of continuously running, valve-based amplifiers.

The second building served as an accommodation block, and is described as having had a small machine gun emplacement nearby, which was not evident during a later site survey.

Destruction by Challenge Anneka

Greycraigs Outdoor Centre, � http://www.geograph.org.uk/user/bill/

Greycraigs Outdoor Centre
� william craig

Some time between 1989 and 1995, the station was transformed into a residential holiday centre for deprived children. This development was carried out as one of the weekly challenges presented to Anneka Rice in the BBC television series, Challenge Anneka. Unfortunately, the format of the programme was such that the work involved was seldom carried out with any regard for the subject's history, as the presenter was given a limited time in which to complete the given task, usually 48 hours, and no cash or budget with which to complete it. Purchasing of labour and material was not allowed, and these had to be obtained through public appeals. With the shooting schedule of the programme dictating the availability of time, scant regard would be given to any remains of the listening post, if any, that might have survived in the old station building, which would have been stripped to make way for the new interior.

The station building has become the Greycraigs Outdoor Centre, Millport, Isle Of Cumbrae, and the Osprey Holiday & Conference Centre.

A report regarding the station was made in 1996, but this was completed after the redevelopment work had been carried out:

Two single storey buildings situated close to the shore at Port Eerie. These buildings comprised a listening post for the underwater defences in the Clyde. They were used for listening for any vessels which might be attempting to penetrate the boom defences crossing the preliminary barrier under the Firth of Clyde. In addition, the living quarters were in the large square blockhouse and a small machine gun emplacement for a lewis or bren gun was situated close by. The blockhouse with the listening equipment inside had large ventilators to allow the heat being created from the many electrical valves to escape. The valves were used to provide a link to the wires connecting under the Clyde to Toward Point in Cowal. The buildings have now been converted into a Outdoor Activity Centre for children and has been completely refurbished thus removing all of the internal wartime features.

Local reports

Local reports describe fixed anti-submarine defences in the Clyde, particularly in the area of Toward and the Great Cumbrae, as Hush-hush Units, and the description of the facilities installed at Eerie Point, further described as connecting under the Clyde to Toward Point may explain how the term came to be applied to them.

Initially, these were thought to have been references to Indicator Loop Station, similar to that a Ganavan, near Oban, but the name, other than as a reference to security (and therefore a little pointless), suggested something else may have involved, and this has now proven to be the case.

From the description of the installation at Eerie Port, there can be little doubt that the equipment was used to carry out acoustic monitoring of the Firth of Clyde using a large number of sensitive microphones, or hydrophones, laid out on the seabed between the Great Cumbrae and Toward. From local reports, the most likely location of the Toward end of the line would have been Oakbank House, said to have been first requisitioned as accommodation for WRENs, and later to have housed a station referred to as a Hush-hush. Local accounts tell of personnel taking small boats out into the firth, where they dropped grenades into the water. This would have been entirely consistent with the operation of such a facility, as the acoustic pulse generated by the resultant explosion could have been used to calibrate the underwater hydrophone array.

Given the level technology in the 1940s, and the lack of modern microprocessor-based adaptive digital filtering and analysis techniques now available, the station operators of such a facility would have been plagued by the effects of ambient noise, which would have arisen naturally from sea, and the effect of waves breaking on the surface and shore; the movement of all the legitimate vessels in and on the Firth of Clyde, and those many miles away, because sound travels considerably further in water than air; the din from shipyards on the Clyde; the sound of aircraft (propellers); local traffic, and even people on the shoreside roads. The description of the stations as Hush-hush units is much more likely to have arisen from the staff and operators, as they fought to silence the unwanted sound signals which interfered with their targets, than any clandestine references, but the double meaning makes for a better story.

No information has come to light about the technical operation of any stations such as that located at Eerie Port, although the US Navy created a modern system based on a similar concept, known as the US Navy Sound Surveillance System (SOSUS), listed in the Links below.

Note that a further station identified as having been associated with Ant-Submarine operations has also been described at Ardhallow. Unfortunately, subsequent re-routing of the local road has erased all traces of this site.