Margate’s New Bathing Pools

Walling in of the Foreshore at Marine Terrace and Walpole Bay

THE two bathing pools recently constructed at Margate are very different from the usual type of swimming bath dealt with in Baths and Bath Engineering, as they are literally nothing more than bathing pools, and simplicity is the predominant feature in the construction and operation.

They are, however, distinctive in their size, as that at Marine Terrace is approximately 2.5 acres in area and the pool at Walpole Bay is over four acres in extent.

The foreshore at Margate running practically the whole of its nine miles of frontage consists of wide sandy beaches, lying at the base of chalk cliffs, alternately with chalk reefs on the foreshore.

The beaches provide safe bathing with a good firm bottom at all states of the tides, but owing to the gradual slope of the beach and the considerable tidal range, low water mark at spring tides may be as far as 300 yd. from the promenades.

Excellent provision has been made by the Margate Corporation in furnishing large sea-bath­ing pavilions and ranges of dressing boxes, but it has been found by experience that the receipts from these undertakings were very much less on days when low tide was about mid-day, and the water’s edge, therefore, a considerable distance from the bathing stations, and in order to facilitate bathing for large numbers of people at all states of the tide it was decided that two pools should he con­structed at the most popular parts of the beach, tine at Marine Terrace in the centre of the town, and the other at Walpole Bay at the east end of Cliftonville.

Details of Construction

The construction of the pools is simply the enclosure of the foreshore by two side walls and an end wall, and the natural beach has been utilised as the floor of the pool, the slope giving a graded deepening of the water to a maximum of about 6 ft. 6 in.

The walls are in all cases founded on solid chalk and built of interlocking concrete blocks, as shown on the accompanying type section. At intervals of 12 ft., old tram rails are concreted into the walls, running about 5 ft. deep into the chalk foundation and up to within 1 ft. of the top of the wall.

An expansion joint is provided between each pair of rails that is about every six blocks in the top course, as it was considered that the bottom courses, being wholly submerged on one side, would not be affected by temperature variations as much as the top course.

In the case of the Marine Terrace pool, owing to the fact that a watertight bond into the chalk could not be obtained without carrying the side walls along the upper beach, an end wall was con­structed at the shallow end. The top level of the wall has been so arranged that both pools are completely submerged at every tide; thus ensuring by way of wave action and dilution a sufficient change-over of water twice a day.

It is an interesting feature that in the case of Walpole Bay pool, there are copious pure fresh water springs arising from the beach within the confines of the walls and the pool is continuously overflowing by the supply of fresh clean water from the floor of the pool.

Overflows are fixed in the top course of blocks, each 2 ft. wide, 6 in. below the top of the wall, so that as the tide recedes the top water line is 6 in. below the top of the Hand-ropes are fixed round the wall and a number of lifebelts; four flights of steps, and two diving boards are provided in each pool.

Three penstocks are fixed in the outer walls of sufficient size to empty either of the pools in about two hours.

Concrete blocks were made in blockyards near the pools and are composed of 4: 2.25 : 1 concrete with rapid hardening cement, and were cast in pairs in wooden moulds and consolidated by vibration.

From the block-yard these were conveyed by Fordson tractor and trailer to the site of the works, and fixed in position by cranes running on tracks laid inside the walls.

It was found economical to use hand-cranes in this case, as the weight of the blocks was only about one ton each, and the cranes were left on the foreshore and submerged at high tide, and this avoided time and expense of moving power cranes out of reach of the water at every tide.

The work was carried out day and night in order to take advantage of every tide, and this was especially necessary in the case of the Walpole Bay pool, where it was never possible to work on the outer wall more than a few spring tides each month, as the neap tides never leave this position.

Electric floodlighting was fixed to the Marine Terrace bathing pavilion, throwing a beam of light down each side wall, and incandescent floodlights and acetylene floodlights were used for the Walpole Bay pool, where it was not practicable at the time to install electric floodlighting.

The pool at Marine Terrace is rectangular in shape, 330 ft. long by 250 ft. wide, and the pool at Walpole Bay is 450 ft. long, 300 ft. wide at the seaward end. and 550 ft. at the landward end.

General

The works were designed in the first place by Mr. E. A. Borg, M.Inst.C.E., the late borough engineer of Margate, now retired and were carried out by direct labour, after modification and improvements in site and method of construc­tion; by Mr. W. L. Armstrong, B.Sc., Assoc.M. Inst.C.E., the present borough engineer.

The estimated cost was about £7,000 for each pool, but they have actually been constructed substantially under that cost. It is also interest­ing to note that the improved receipts at both bathing stations have amply justified the corporation’s enterprise in providing these extensive pools.

Frequent tests taken of the water indicate that the purity of the water is not the least inferior to that of the open sea.