The building of St Colman’s Cathedral, Cobh, 1868-1915
26 August 2019
The foundation proved difficult as they had to be built on solid rock, and extensive excavations had to be carried out with a depth of 7.3m on the south elevation and 1.2m on the north elevation.
St Colman’s Cathedral, Cobh, Co Cork, is a neogothic structure which is modelled on three French cathedrals: Chartres, Amiens and Reims, which were all built in the 12th century.
There is also some resemblance to Lisbon Cathedral, which is a 13th century Romanesque style with a Latin cross outline. Other churches designed by Pugin and Asling include St Peter and Paul, Cork; St Mary’s Cathedral, Killarney; and the Daniel O’Connell Memorial Church, Caherciveen, Co Kerry.
The cathedral was built during the reign of three bishops: Bishop William Keane (1857-1874) a native of Imogeela; Bishop John McCarthy (1874-1893), a native of Fermoy; and Bishop Robert Brown (1894-1934), a native of Charleville.
It sits on the site of the existing St John the Baptist church, which was demolished in 1858 to make way for the enormous and condensed building, St Colman’s Cathedral.
The existing building was founded on sloping ground following the ground profile of the existing sandstone rock shelf. The new cathedral, which was being planned for 10 years, was designed by Edward Welby Pugin (Kent, England) and George Coppinger Asling (Little Island, Cork).
Its structural implication was designed and checked by Alexander Deane, a consulting engineer from Cork, as there were excessive weights and loading to be dealt with in the walls and pillars of the structure.
When Pugin died, Asling joined forces with Tomas Aloysisus Colman, a native of Dublin. The foundation proved difficult as they had to be built on solid rock, and extensive excavations had to be carried out with a depth of 7.3m on the south elevation and 1.2m on the north elevation.
This was 1868 and they only had the use of a steam driven plant. The foundations were built with sandstone rock, which was sourced from Carrigmore and Linseys quarries. The foundations were built to a level 1m below ground level.
The foundations were designed to sit on the solid rock and were stepped to achieve a width of 2.2m. The foundations for the nave pillars were similar of construction, consisting of sandstone rock quarried and transported to the site by horse and cart.
The stone work was carried out by local stonemasons employed by Michael Meade, an established contractor from Dublin. The foundations were backfilled with similar stone from the nearby quarries.
Consisting of a limestone block, 2.2m x 1.2m high x 1.5 long, it was quarried at Fitzgerald’s quarry, Carrigacrump, Aghada, as the cornerstone and the starting point issued from the Cloyne dioceses with the inscription, “30th September 1869, Bishop William Keane”.
Clerk of works
Full credit must go to Charles Guilfoyle Doran who dedicated his working life of 40 years to the construction of St Colman’s Cathedral. He was an engineer and architect, and he had a lot of experience in most trades. He was a native of Dunlavin, Co Wicklow, and lived his life in Cobh and Cork.
The external walls were built of Dalkey blue granite and transported by boat to Cobh from Dún Laoghaire; initially the stone was transported by light rail from Dalkey to Dún Laoghaire.
The stone landed in Cobh at Ballast Quay (now Lynch’s Quay) and was transported to Ticknock where it was cut and shaped for it chosen location.
The granite stones weighed 0.3 tons or 300Kg each and were hoisted into position by a combination of methods, such as steam gantry, horse hoisting by rope and stageing. The external walls varied in width from 1m to 2.2m to accommodate the spine columns, which supported the flying buttress at roof level set at 5m centres.
The internal stone and decoration consisted of a combination of stone work from Bath stone on the wall infills with Portland stone for the spine column construction.
They were founded on the sub-foundations with a Liscarroll limestone block 880mm cut to an octagonal shape; on top of this you had the shoe of the column formed from Italian marble 250mm thick with curved edges.
The columns consist of Fermoy red marble made up of three segments spigot and socket joined to each segment. The top of the pillar has a collar stone of Italian marble curved to carry the limestone section radiating out to support the vaulted ceiling and Triforium walls.
The nave columns are designed to carry loading of up to 200 tons.
Side isles ceilings
These consist of vaulted ceilings with four spine beams of Portland stone springing from each corner to a universal point in the centre of each vaulted ceiling section 7m square.
The infill stone is bath stone laid on temporary support staging to form the curve effect and solid structure.
This consists of Californian pitch pine set to a 5.7m radius springing from the nave columns set at 11.4m spacing and fixed to support timber work curved to the radius in semi-circular and quadrant lengths. A timber staging was erected to install the ceiling by dedicated carpenters and helpers.
Constructed of Californian pitch pine with the rafters set at 60 degrees springing from the Triforium walls. The rafters were sheeted with pitch pine sheeting and covered with sarking felt and roof batons at 300mm centres on which the Belgium blue slate was fixed in a pattern up the roof face.
The flying buttress set at 5m centres at a 45 degree angle supporting a 6.4m width between the walls, that is, external walls and Triforium wall above the nave pillars.
The flying buttress act both as a tie and a strut and loads of approximately 100 tons or greater. The load is transferred down the spine columns into the foundations at ground level.
Tower and spire
Constructed from 1911 to 1915, it consists of a square tower of Newry granite 7m square 25m high housing the organ and bell Carillion.
The internal area of the tower consists of a series of columns substantial to carry the octagonal spire. The spire is 35m high with an overall height of 87m and radiates from the octagonal base to a point some 35m above on which sits the steel cross which was blessed by Bishop Brown before its erection.
Cathedral ground boundary and support walls
The boundary of the cathedral was developed and constructed circa 1900, and this involved the construction of the boundary walls and buttress wall at the rock steps.
The boundary walls stand vertical, and consist of Mallow limestone and red sandstone. The buttress wall has an intricate design to uphold the road load and foundation for the grounds of the cathedral.
The buttress wall founded on solid rock consists of a series of piers set at 70 degrees and spaced at 3.65m centres of limestone blocks. Concrete arches were constructed to span between piers to uphold the parapet piers and railings.
The workforce consisted of carpenters, labourers, helpers, horsemen, stonemasons and generated 2.76 million man hours over the 47-year building programme. It was a dedicated achievement to the craftsmanship, skills and safety concerns of working at heights of 87m.
This workforce deserves great credit and were guided by Charles Guilfoyle Doran. The hourly rate was about 11 pence per hour and fluctuated during the construction period.
St Colman’s Cathedral cost £235,000 to build for 1,526m2, which equates to £154 per m2. Today it would be a challenge for any contractor to achieve the workmanship and detail that was expressed in the internal and external build of St Colman’s Cathedral. A global estimate in today’s market would indicate a value of about €20,000,000.
Author: Donal Collins, RE capital programmes, southern region, Irish Waterhttp://www.engineersjournal.ie/2019/08/26/the-building-of-st-colmans-cathedral-1868-1915/http://www.engineersjournal.ie/wp-content/uploads/2019/08/c1main.jpghttp://www.engineersjournal.ie/wp-content/uploads/2019/08/c1main-300x300.jpgCivilconservation,construction,Cork