The Harbour Sluice
Featured in the March 2010 handbook.
A worryingly recurrent rumour keeps surfacing about the old Harbour Sluice, which some ‘experts’ fondly imagine can solve the problem of silting if once more opened up. Common sense, however, should query as to exactly why it was blocked off in the first place if it ever had any utility, which I can assure the reader, it never did. History can teach us salutary lessons if we only acknowledge its records, and in the case of the Harbour Sluice that lesson was hard-earned by the Pier and Harbour Company which, in 1826, incurred one of their most futile expenditures ever in installing it.
As one of its acts of public benefits to the town (and to protect its own interests as far as the controversial sinking fund was concerned ) the Pier and harbour Company had financed the building of the stone groyne at the Nayland Rock when Marine Terrace was being constructed, hoping that would assist in trapping sand in the bay, where there was then much beach stone. By 1826, the point was proved, and by altering the tidal flow in the Bay with that groyne their Harbour was choking with sand and seaweed which accumulated there also.
It was decided to form an arch through the Pier, 9 feet wide and 9 feet high, its bottom being paved with stone to act as a cart road with the vertical sides being 6 feet high to the spring of the arch. That tells the reader just how much sand has built up both inside and outside the pier since then as only a few feet of the top of the arch now show. The opening on the seaward side was fitted with an enormous and strongly constructed oak door, and even in 1826 the silting had already caused the level inside the Harbour to be 6 feet higher than on the seaward side. The reason for the silting was that stone groyne, but then, just as now, any amount of spurious reasons were advanced, such as the rotting of seaweed driven in by gales or the settling of sand churned up by the paddles of the steam boats. In fact, one proposal actually suggested that once the sluice was opened up a steam boat should be stationed stern- on to it and paddles run at full speed to churn up the sand and drive it through the wall.
The previous method of dredging the Harbour had been the filling by hand of a lighter, which was then taken out to sea and the spoil dumped. This method was expensive at 2 shillings per ton. The economics of using the sluice as a cart road brought the expenditure per ton right down to sixpence. The whole scheme cost £853.00 a lot of money in those days, but it was an abject failure. After all, how could an arch that size pointing in the direction of the Kings Stairs flush out the Harbour? All that happened was that the water at the King’s Stairs became very agitated, badly affecting the boatmen who complained very loudly about the effect on their livelihood. There was no improvement in the silting, and the sluice almost certainly let more sand in. The process of dredging by hand into house drawn carts continued unabated as the only practical solution to the continual problem of silting. In actual fact, it is largely caused by the continual eastward drift of sand and man’s interference with tidal flow.
A violent summer storm in August, 1832, caused severe damage to the fabric of the Stone Pier, with part of it subsiding. Another feature of this storm was the tearing off from its supports of the great oak gate of the sluice, and although this damage was repaired the future of the sluice was limited. During the following winter 5000 tons of silt were removed from the Harbour, partly by horse and cart, and partly by barrow.
In 1838 the useless sluice was block in and a small guillotine gate fitted in it, still extant to this day but long abandoned. The sluice was useless and a waste of money, as any future expenditure would also be!