Signal tower

The National Monuments Service's description

Situated on flat ground with a steep curving slope to the N which drops down to the coastal plain, (83m OD). The surrounding area consists of enclosed pasture defined by stone walls. It is located within a large circular enclosure of possible Neolithic date (Kelly 2018) that consists of an external ditch and an internal bank (SL012-008001-). A mortared rubble stone wall runs from E to W across the enclosure, dividing off the signal tower and the northern third of the enclosure from the southern two thirds. The wall was an element of the enclosed landscape in which the signal tower is set. Within the large enclosure there is a smaller sub-circular ditched enclosure (SL012-008002-) suspected to be an early medieval enclosure. The site has unobstructed views in all directions. Rathlee Signal Tower (SL011-025001-), located c. 10.6kms to the WNW, is currently obscured by intervening forestry. Knocklane Hill Signal Tower SL007-057----), located c. 16.6kms to the NE, has been largely demolished\collapsed and cannot be seen from the site.

An early nineteenth-century (c. 1804-6) two-storey square-plan signal tower, built with roughly coursed rubble stone masonry (int. dims. 4.31m N-S x 4.52m E-W)). The signal tower is particularly well preserved, surviving to its full height (H. c. 11.25). The N wall is the tallest with the other sides being slightly lower, reflecting the slight slopes\topography of the area adjacent to the tower. The N wall features a square-headed doorway to the centre at first floor level that would have been accessed via a retractable ladder. The doorway retains cut stone block-and-start surrounds, cut stone threshold, and cut stone lintel over with central projecting keystone. The door is protected by a wide machicolation over supported by three sloping cut stone corbels with two cut stone slabs providing the base at parapet level. The machicolation features short narrow gun loops in the centre of each of its three walls. The E and W walls each feature two square-headed windows at ground and first floor levels. The N ground floor window on the E wall was later opened up to form a ground floor entrance. Cut stone block-and-start surrounds, cut stone sills, and cut stone lintels with projecting keystones are retained to all window openings apart from the window opening later widened to create a doorway. The first floor windows on both the E and W walls have been blocked up with neat rubble stone masonry. The S wall features a central slight outward bulge that houses the chimney flue. A partially collapsed rubble stone chimneystack is located on top of the centre of the S elevation. A small horizontal chute passes through the E side of the S wall at ground level, connecting to the top of the semi-basement level. The SE and SW corners of the signal tower are protected by bartizans supported by three sloping cut stone corbels, with two large stone slabs providing the base of each bartizan at parapet level. The bartizans project straight out from the wall and feature sharp curving corners on the diagonal points. The bartizans feature short narrow gun loops in the centre of each of their four walls. The parapet survives to all elevations, which extends around the bartizans and the machicolation over the door, and retains fine chamfered cut stone coping over.

The internal space consists of a semi-basement level, which is almost entirely infilled with soil, a ground-floor room with a split mezzanine level, a first-floor room, and a low attic level. The flat roof had been accessible from the attic level. The floors and the roof of the building had been wooden and were carried in the thickness of the wall. No parts of the floors or the roof have survived but rows of joist-holes indicate their former positions. The internal walls are covered in a layer of smooth lime render, although this does not extend into the semi-basement level. The S wall features central fireplaces flanked by segmental-headed alcoves at the ground floor and by square-headed alcoves at first floor level. The chute which passes through the S wall opened up into the semi-basement level below the position of the E ground floor alcove. A square sectioned internal drainage channel runs down the SE corner of the building. This is believed to have brought rainwater from the roof to storage barrels in the semi-basement.

The signal tower was part of a system of over 80 signal stations constructed by the British Board of Ordnance in the first decade of the 19th century to warn of the approach of a French invasion fleet. Signalling between sites was accomplished using a naval signal post. The system formed a continuous chain from Dublin Bay running clockwise all the way around the coast to Malin Head in County Donegal. It was abandoned by the mid-1810s when the threat of a French invasion diminished (Kerrigan 1995, 157-66).

Compiled by: Stuart Rathbone

Uploaded on 08\11\21

Images:
SL012-008003-.01 N exterior
SL012-008003-.02 E exterior
SL012-008003-.03 S exterior
SL012-008003-.04 W exterior
SL012-008003-.05 SE Oblique exterior
SL012-008003-.06 SW oblique exterior
SL012-008003-.07 E interior 1
SL012-008003-.08 E interior 2
SL012-008003-.09 E interior 3
SL012-008003-.10 N interior 1
SL012-008003-.11 N interior 2
SL012-008003-.12 N interior 3
SL012-008003-.13 S interior 1
SL012-008003-.14 S interior 2
SL012-008003-.15 S interior 3
SL012-008003-.16 W interior 1
SL012-008003-.17 W interior 2
SL012-008003-.18 W interior 3
SL012-008003-.19 E exterior drawing
SL012-008003-.20 N exterior drawing
SL012-008003-.21 W exterior drawing
SL012-008003-.22 S exterior drawing
SL012-008003-.23 E interior drawing
SL012-008003-.24 N exterior drawing
SL012-008003-.25 W interior drawing
SL012-008003-.26 S interior drawing
SL012-008003-.27 Plan of site
SL012-008003-.28 Field wall to site

References

Kerrigan P.M. 1995 Castles and fortifications in Ireland 1485-1945. Cork. The Collins Press.

Rathbone, S. 2020. ‘The Construction, Survival and use of Signal Defensible Guard Houses in Connacht and Ulster’; unpublished PhD Thesis, Institute of Technology, Sligo

Kelly, D. 2018 'Carrowmably: A comparative geophysical and landscape study in West Co. Sligo. Unpublished B.Sc. (Hons) thesis. IT Sligo