Mr Pitt's expensive ditch was dug to deter old Boney

It seemed a good idea at the time.

Friday, 31st March 2017, 6:00 am
Updated Tuesday, 9th May 2017, 8:17 pm
A view of the Royal Military Canal. Along with Martello Towers it was intended to be a key defensive position in the event that the French invaded Englands south coast during the Napoleonic Wars. By the time the costly canal was completed in 1808 the French threat had receded.

It seemed a good idea at the time. Napoleon was gathering a massive army of 200,000 men at Boulogne intent on invading England.

He even called his force the “Armee d’Angleterre”. The low-lying coast between Folkestone and Hastings was considered particularly vulnerable to a landing. So when Lieutenant-Colonel John Brown proposed the construction of a 28 miles long canal arcing around the landward edge of Romney Marsh as a defence against the French his idea found enthusiastic support, not least from Prime Minister William Pitt the Younger.

Unfortunately by the time the Royal Military Canal was completed in 1808, the threat of invasion had long receded, largely thanks to Nelson’s victory at the Battle of Trafalgar in October 1805. The waterway had become an enormously expensive white elephant denounced by many as a complete waste of money. The criticism persisted for years; writing in 1822, whilst undertaking one of his “Rural Rides” through Sussex, the radical journalist William Cobbett scornfully observed: “Here is a canal made for the length of 30 miles to keep out the French. Those armies who had so often crossed the Rhine and the Danube were to be kept back by a canal 30 feet wide at most!”

In the Second World War the Sussex coast was again in danger this time from an expected German invasion. The Royal Military Canal was called up for service as a defensive line and concrete pillboxes were constructed along the length of the waterway.

What Cobbett may not have known is that the canal was originally planned to be twice as wide and twice as deep as it actually ended up. But whatever the waterway’s dimensional shortcomings, creating the Royal Military Canal was an impressive undertaking even though it got off to a stuttering start. Work began near Hythe in October 1804 but by next May just six miles had been completed. Frustrated Premiere Pitt intervened and sacked the contractors. He replaced them with the Quartermaster-General’s staff. Progress immediately sped up and some 1,500 men became engaged in the construction. Civilian “navies” did the digging of the canal while soldiers were deployed to build a raised canal side rampart using excavated soil.

A road was built on the inland side of the canal behind the rampart. This meant troops could march unseen to any location where an enemy threatened a crossing. The course of the canal was “staggered” to create salients where defenders could deliver enfilade fire. The plan called for artillery batteries to be stationed every 500 yards and Martello Towers were built to guard the vital sluices that controlled the canal’s water level. Easily dismantled wooden bridges allowed the local inhabitants to pass to and fro.

The statistics relating to the waterway are impressive. For starters it is the third longest defensive structure in Britain, surpassed only by Offa’s Dyke on the Welsh border and Hadrian’s Wall. Just over 20 miles of the canal were dug by hand with the remaining distance incorporating stretches of the Rother and Breed rivers. Construction cost a whopping £234,310, a huge sum to expend in Georgian England. Romney Marsh folk dubbed the canal “Mr. Pitt’s Ditch”.

Seeking some justification for the painfully expensive project, the authorities claimed the canal would also serve as a deterrent to smuggling, a practice endemic on the marsh. Guardhouses were installed at crossing points but there’s no evidence that smuggling was impaired. For just a few pence and the occasional bottle of grog, poorly paid sentries simply turned a blind eye as the “gentlemen” went by.

In the Second World War the Sussex coast was again in danger this time from an expected German invasion. The Royal Military Canal was called up for service as a defensive line and concrete pillboxes were constructed along the length of the waterway.

As another measure to part recoup the massive investment, the canal was opened for commercial use and tolls were levied on travelers using the military road. A regular barge service connected Hythe and Rye. Even so, canal and road traffic was light and the income hardly covered the maintenance costs. The opening of the Hastings and Ashford railway in 1851 prompted a significant downturn in canal usage.

In the middle of Queen Victoria’s reign a Government desperate to end the burdensome subsidies was delighted to lease the length of canal from Iden Lock to West Hythe to the Lords of the Romney Marsh for 999 years for a rent of just one shilling per year. The town of Hythe acquired another stretch for recreational purposes while the waterway west of Rye also went into private ownership. Canal business continued to decline. The last ever toll levied on a barge was made at Iden Lock on 15th December 1909. In 1935 the Royal Military Canal was requisitioned by the War Office in response to the growing menace of Hitler’s Nazi Germany.

The banks of the waterway became studded with concrete pillboxes and when the blitzkrieg of 1940 saw Germany occupy the northern coast of France, great blooms of barbed wire and other obstacles were put in position. Like that of Napoleon, Hitler’s planned invasion of England - “Operation Sealion” - never happened but after the war it was revealed a prime target for the first day was an airborne landing to seize bridges over the canal so that seaborne invaders with armoured vehicles could quickly advance into Sussex and Kent.

Under the auspices of the Environment Agency, today the Royal Military Canal has a vital peacetime role in sustaining the environment of Romney Marsh. In summer if lack of rain sees the ditches dry out then canal water can be pumped out to top them up.

Conversely, winter floodwater can be pumped from the marsh and into the canal. It’s a very serendipitous arrangement