Thomas Omer was a canal engineer from Holland was invited to Ireland in 1755 by the Commissioners of Inland Navigation to act as their engineer. During the second half of the 1750s and the 1760s he was involved in the planning and construction of the Grand Canal, the Newry Ship Canal, and of the Lagan, Boyne, Shannon, Nore and Barrow navigations.
The 11th Lock marks the start of Omer’s version of the Grand Canal, a wide canal with large locks running through land that was easily and cheaply purchased. 11th Lock, now foreshortened, has just a 3.5 M rise. Construction of the original canal began on this section in 1757, using cut limestone from a quarry near Gollierstown (above 12th Lock) and by 1763 Omer had overseen the building of 12 miles of the canal with three locks (not 11th, 12th and 13th), six bridges, seven aqueducts and four lock-houses – all at a cost of £57,000. Thereafter construction focused on the stretch towards the River Morrell (above 15th Lock) in order to secure a good water supply. At this stage the Corporation of Dublin became involved as they saw the Morrell and the canal as a potential source of fresh drinking water for the city. Between 1763 and 1777, however, very little progress was made with the canal.
The Grand Canal Company, which had been set up in 1772 to ensure the completion of the canal by attracting more investment to finance construction across the Bog of Allen to the West and towards Dublin in the East. In 1777 they consulted with another engineer, John Smeaton, and his assistant, William Jessop to advise them. Smeaton was critical of some of Omer’s work and his report led to a smaller-scale canal being constructed outside of the 11th – 13th Lock section – Smeaton advised reducing the generous locks that Omer had built (42m by 6 m / 137 ft by 20 ft) to 18m by 4m (60 ft by 14 ft), which would bring about considerable savings in the total cost of the construction of the canal. – more of which later.
It is noticeable that the canal itself, and not just the locks, were grander in scale under Omer’s supervision and the canal, despite being overgrown in places, has a wide feel to it along here.
Omer’s plans for canal buildings were as large in scale as the canal itself and the Lock Keeper’s House above 11th Lock on the Northside (now in ruins) is evidence of this – a two storey building. What kept the cost low, apart from the low purchase price of the land, was the relatively flat level – it is 3KM between the 11th and 12th Locks. You appreciate this as you speed along this section of the cycleway unless there is a strong Westerly wind prevailing.
There is not need to go down by the side of the ruin.
The cache is a small camouflaged tubular vial, log only BYOP