archaeological & built heritage assessment - The Heritage Council

completed in 1817 and the Ballinamore and Ballyconnell Canal completed in 1859 which provided a link
from Belfast to the Shannon via the Lagan and Ulster canals.
The belief that canals would transform the Irish countryside and especially the midlands by encouraging
industry and agriculture (the latter being associated with drainage schemes) did not prove correct. They
were not a commercial success primarily because they did not tap areas of mineral reserves or reach
large industrial centres but rather relied mainly on the transport of bulky agricultural products. While
they carried a substantial proportion of traffic in their corridors in the pre-railway era, the revenues
generated were not sufficient to cover costs. There were however significant landscape impacts such as
the development of canal villages, lock-keeper’s houses, warehouses and hotels for overnight passengers,
all of which were constructed to a high standard, and thus have become an enduring element within the
study area.
The Shannon Navigation
In 1755, following surveys and decisions taken by the Shannon commissioners to undertake navigation
works, it was recognised that at Roosky, a lateral canal and lock were needed and at Jamestown it was
possible to by-pass the shallows by cutting a canal across the natural loop in the river. It is noted that the
navigation was completed to Roosky in November 1769, while the Jamestown Canal was probably
finished in the early 1770s (Delaney 1988).
Expenditure on public works was severely curtailed from the 1770s and many areas of the navigation
were unfinished or fell into disrepair. A parliamentary committee was set up in 1783 to investigate the
condition of the canal system and it was resolved that the entire navigation should be put into repair and
extended into Lough Allen. The presence of coal and iron in the mountains surrounding Lough Allen also
provided an impetus to open up the navigation in this area. At this time, Colonel Tarrant estimated that
the cost of extending the navigation into Lough Allen would be £12, 000. In 1794 a survey carried out by
John Brownrigg had noted that the level of the lake was three or four feet higher than some time
previously due to silt being brought down by the Arigna river, which discharged into the River Shannon
below the point where it left the lake and was gradually blocking the exit. Colonel Tarrant attempted to
overcome this silting problem caused by the winter floodwaters of the Arigna river by making an artificial
cut which turned the river directly into Lough Allen instead of into the Shannon but these works seem to
have ceased shortly afterwards and no improvements were carried out further south (ibid.).
Detailed engineering reports dating to 1801 indicated that at this time the lock at Roosky needed new
gates and the Jamestown lock also needed gates, there were breaches in the banks of the canal and it was
stated that ‘much mischief will be done here in the ensuing winter when the Shannon rises three or four
feet higher for there is no person now empowered to lay out a shilling to prevent it’ (ibid.).
The completion of the Royal Canal to the upper Shannon in 1817 brought an impetus to improve this part
of the Shannon navigation. Extensive repairs were carried out on the Jamestown Canal and harbours were
built at Carrick-on-Shannon, Dromod and Drumsna. Access to Lough Allen and the Arigna coalfields was
essential in economic terms and an original scheme to make a lateral canal to the west of the river
Shannon was abandoned in favour of constructing a canal to the east of the river all the way from
Battlebridge to Lough Allen, passing through Acres Lake en route. Work was completed on the canal and
opened to traffic in 1820.
19