Category Archives: Engineering and construction

The sounds of Pontcysyllte

The latest soundscape from the Canal & River Trust features the Pontcysyllte Aqueduct with, on one side, the canal basin at Trevor and, on the other, Whitehouses Tunnel. Take five and a half minutes off to listen.

The site itself is well worth a visit, even if you just walk across the aqueduct and back. It’s off the A5, Telford’s road: after coming from Ireland by ferry, you could take that road — older, slower but more scenic — from Holyhead instead of the A55 coastal route.

h/t our Yorkshire correspondent

Header photo 20191202

Looking towards Clondra Lock.

The new header photo 20191102

Lanesborough bridge

Scrubbing the Sheugh

Monaghan Town meanwhile got €57,600 to clean a section of the Ulster canal, and carry out appropriate planting and turn this section of Ulster Canal Greenway into a haven for wildlife […].

From The Anglo-Celt 31 October 2019

Another estuary quay

Here is a page about Ringmoylan, a quay on the south side of the estuary.

 

A gale at Limerick

Doubtless there must have been a pretty considerable storm at Limerick on Thursday week; though the following Hibernian account of it, in the Limerick Chronicle, goes somewhat beyond our sober and humble notions of the style proper for narrative.

That comment was made by the Spectator of 7 December 1833. Odd that a mag later edited by Boris Johnson should once have been devoted to “sober and humble” narratives. O tempora o mores.

Here is the Chronicle report as the Spectator quoted it:

A violent gale of wind set in at WNW, accompanied by occasional heavy showers of rain; and on the same evening, the gale assumed all the appalling characteristics of a most furious hurricane.

Throughout the night, the scene was terrific in the extreme, and the streets presented a most desolate aspect. Nearly all the public gas-lights were extinguished; and the howling of the storm, as it swept in pitiless squalls through every street, lane, and alley, struck terror to the hearts of every inmate of those mansions which suffered more or less from its destructive power.

A spring-tide, raised by the storm beyond its usual boundaries, dashed with desperate force against the quays, rolling a vast mass of water over the docks, etc and presenting one continuous sheet of liquid foam, at either side of the river for two miles. Several boats were thrown out of the docks upon the quay, where they were left high and dry at low tide. The vessels of the Shannon Yacht Club, laid up for the winter season at anchorage in the Abbey river, were driven against the salmon-weir bank, but received no material injury.

The strong banks enclosing the Abbey river (island and salmon-weir) were broken up, and the waters rushed in, deluging the fields on both sides to a wide extent. The cattle grazing there, cows and sheep, were saved with great difficulty. The long-pavement, or causeway, from Quinpool to the Thomond Gate Distillery, was inundated, and the fields around flooded.

The yards of the city gaol were full of water, and the tide came up to its very gates, as it did also to the verge of the flagging on Arthur’s Quay. The underground kitchens in houses adjacent to the river were from one to two feet deep in water. It is worthy of remark, that a few hours before this dreadful commotion, the quicksilver fell rapidly to a degree so low as we scarce ever remember.

The horses of the Ennis coach had to wade knee-deep several miles of the road, especially about Cratloe, without a vestige of the usual landmarks. The salmon weir received considerable damage, a great portion of the large timber-work having been torn up and sent adrift. Some of the strongest houses in the city literally rocked in the blast like a cradle. A house building off William Street, which wanted merely the roofing to complete it, was hurled to the ground, and became a pile of rubbish.

 

Romance on the Shannon

Elopement

We are informed that Maurice O’Connell Esq, MP for Clare, has proceeded to Scotland on a matrimonial excursion. Our correspondent states that on Saturday morning the Member for Clare induced Miss Scott to leave her father’s residence at Cahircon and proceed with him to Gretna Green. The Lady is young, handsome, and an heiress.

Wexford Conservative 3 October 1832

A letter has just arrived in town from a friend of the member for Clare, which states that, on Saturday morning, a Miss Scott eloped from Cahir Con (between Knock and Kildysart), with Maurice O’Connell, MP. They crossed the Shannon in a pleasure-boat, and landed at Shanagolden, county of Limerick. From thence they proceeded in a chaise through Limerick. Their route will probably be through Waterford to Bristol, and thence northward to Gretna Green. Miss Scott has, or will have, it is said, £20,000.

Spectator 6 October 1832 citing “Dublin Paper”

It’s not safe to believe conservative papers.

Marriages

At Tralee, by special licence, by the Very Rev Dr McEnery, and afterwards at Kenmare, by the Rev William Godfrey, Rector of that parish, Maurice O’Connell, MP for the County of Clare, to Mary Frances, only daughter of Bindon Scott Esq of Caheracon in that County.

Limerick Chronicle 3 October 1832

Who said Cahircon was boring?

Mind you, Mary Frances may have inherited less than she expected. Perhaps if her father had spent less on the house of the dead, he might not have ended up as the only Shannon Estuary landlord unable to pay his debt to the Shannon Commissioners. His estate was offered for sale in the Encumbered Estates court in 1854.

Navigating Ardnacrusha

The Western Mail & South Wales News of 19 April 1929 had an article by M Franklin Thomas about “Ireland’s Big Engineering Scheme”. The article was illustrated with a map and three photographs were reproduced on the newspaper’s “picture page”. It had a couple of interesting points about the headrace and tailrace considered as navigations; I can’t recall seeing these points made elsewhere.

Current

This [headrace] canal is level, but a flow of about 3½ miles per hour will be maintained owing to the water released through the turbines and navigation locks.

I don’t recall seeing a figure for the current. I presume that that is with three turbines running flat out.

There is an interesting account of the laying of the concrete apron that protects the banks against the “wave action set up by navigation, and the flow of the stream, wind, &c”. And the lock was to have an “ingenious arrangement by which the entering streams of water neutralise each other’s effect”.

Tailrace

Mr Thomas says

The tail race is one mile and a half long, cut from the solid blue limestone, and one of the most interesting points was the method adopted to permit barges to ascend the tail race against the enormous scour from the turbine discharges.

A special navigation channel is cut from the locks to a point some 200 yards below the outfall, and the bed of the tail race rises 20ft in the mile and a half, so that the depth of water will be 35ft at the outfall from the turbines and 15ft at the junction with the Shannon.

This will give a cushioning effect, and the rate of flow will be thus reduced to enable barges to navigate upstream. A bend is also provided where the special navigation channel joins the tail race and the rate of flow is estimated to be the same as that of the head race — 1.5 metres per second, or about 3½ miles per hour.

I would be glad to hear from anyone who can cast further light on this, and especially on whether the rising bed does have the intended effect.

The level of the Shannon

I want to see these 16 pinch points dealt with because in removing them we will drop the levels of the Shannon downstream of Athlone right down to where Deputy Harty lives. We are talking about dropping the level of the Shannon a foot and a half. The number of people who would benefit from this – the local farmer, the local business, BirdWatch Ireland – is enormous. The Government is committed to putting huge money into this.

Kevin Moran TD (Ind, Longford-Westmeath), minister for draining the Shannon,  in a Dáil Topical Issue Debate on Flood Risk Management on 16 October 2019.

I wonder which level he’s talking about.

Royal Canal greenway

Big it up, says Sarah Carey in the Indo.