Mayo memories: Old Pontoon bridge needed replacing in the 1960s

By Tom Gillespie

PONTOON bridge is on one of the main roads connecting the towns of Ballina and Castlebar. The road, well known for mountain scenes and lake views, is much used by tourists during the summer months.

A bridge was built there in 1925 over the narrow waterway connecting Loughs Conn and Cullin. It was a single span of about 35 feet, carried by plate girders, with concrete parapet walls.

As a bridge it was strictly functional; it could hardly be said to fit either the scale or character of the magnificent landscape.

One of the main aims of the Moy Drainage Scheme, started in 1960, was to lower the water levels of Conn and Cullin by deepening and widening the waterway between the two lakes.

It was intended to adapt the bridge to the new conditions by extending the foundations of the abutments down to the new channel levels - an operation technically known as underpinning.

This plan was abandoned when it was discovered that the abutments were founded, not in rock, as expected, but on what appeared to be a mixture of boulders and gravel.

It would not be safe to underpin in those conditions. So a new bridge was needed.

A number of technical factors dictated that the new bridge would be built some distance to the Ballina side of the existing bridge.

The position selected for the bridge left no fears about inadequate foundations.

There was plenty of solid rock; in fact a considerable amount of rock had been excavated.

The site also fitted in with the county council’s plans for aligning the road at Pontoon.

The survey of the site, as well as the design was undertaken by the Office of Public Works (OPW) engineering branch as part of the work of the Moy Drainage Scheme.

A number of different bridge designs were considered. The object was to ensure that the new bridge would give a pleasing effect when viewed against a backdrop of lake and heathered mountain.

A structure which would be economical, structurally sound and pleasing to look at was the ideal aimed at. An arch bridge was found to be most attractive.

The design adopted is circular and 12½ feet high over the abutments with a span of 61 feet. The arch is 36 feet from inlet to outfall; long enough to carry a carriageway 21 feet wide, two footpaths, each 6½ feet wide, and parapet wall.

The arch and spandrel walls, which retain the filling round the arch, are built of reinforced concrete but the walls have been faced with stone.

The stones used came from a bridge demolished elsewhere in the county during road works. They were ideal for the purpose and went a long way towards giving a mellowed appearance to the new structure, enabling it to harmonise with its immediate surroundings. This was a point which much attention had been given at the planning stage.

In the complete bridge the only concrete exposed to view is the face of the arch ring which stands two inches proud of the spandrel walls.

A steel railing of slider design was mounted on the parapet at each side of the bridge to give an unobstructed view of the lakes.

On completion of the bridge the new channel between the two involved the removal of 2,000 cubic yards of rock, which had carried the bypass while the new bridge was being built.

The rock mass stood 26 feet over the new bed level and was as close as two feet to the completed bridge.

A novel feature of the Lough Conn side of the new bridge was two walled-in platforms of flat rock high above the water which afford excellent views of the lake.

These outcrops might well have been a source of danger had they not been protected. Extensive realignment and other improvements to the road on each side of the bridge had now been carried out by the county council.

This had been done to improve the amenities of the area and the setting of the new structure.

During the early stages of the work, while blasting was in progress, a bronze rapier, in excellent condition, was found lying on top under several feet of overburden. It is now in the National Museum, where it has been attributed to the Middle Bronze Age, circa 1200 B.C.

TUCKER’S LAKE WATER SUPPLY SAGA

On other matters of lakes in the county, on Wednesday August 13, 1952, a state of emergency was declared in Castlebar, The Connaught Telegraph reported, when, after the Tucker’s Lake pumping station broke down, its three institutions - the County Hospital, Mental Hospital and the County Home - were left without water.

The county manager ordered the fire brigade into action and the town was solely dependant upon the fire brigade for a supply of water.

The paper reported: “For a considerable period of years now the widely publicised Castlebar water supply scheme has been unsatisfactory despite the fact that a sum in the vicinity of £40,000 has been expended on it.

“New pipe lines were laid down but, fantastic as it may seem, there is no water supply to feed the mains.

“The Tucker’s Lake pumping plant, disused for a number of years, was pressed into service recently, and it helped somewhat to provide a supply that was always at low pressure. When this source failed on Wednesday the town went dry.

“A a result of the water shortage, dreadful conditions prevailed at the County Hospital, the Mental Hospital, and the County Home.

“The patients had not been bathed for the past week, toilets were dry, and, for the most part, water was being drawn by buckets.”

The frightful position of things was causing grave concern to the medical and nursing staffs, whose work was really becoming a nightmare.

At the Mental Hospital, with its 1,300 population, the position was precarious.

The large building was completely without water.

In the County Home, the position was just as bad and inmates could be seen drawing water for cooking purposes.

In the County Surgical Hospital, where water was absolute essential, all the taps were dry and the medical authorities and nursing staff viewed the position with alarm and anxiety.

The Connaught Telegraph reported: “We appealed to the Department recently to intervene in the matter of the Castlebar water supply. Our appeal went unheeded.

“We are weary and sick of pointing out the position of things to the urban council and engineers.

“This crisis was bound to happen. It is, perhaps, better that it did, for something now (1952) will have to be done if the population is not wiped out by fever.”