OUGS Visit to Samphire Hoe
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OUGS visit to Samphire Hoe 17th August 2014 The channel tunnel and how the spoil at the foot of the cliffs is managed. How Chalk and flint are formed. How the channel developed. Leaders: Les Richmond, local geological and historical guide. Melanie Wrigley, ranger with the White Cliffs Countryside Partnership. Rain hung in the air and the visit played out under a grey gloomy sky. A south easterly wind channelled the clouds along the coast and thankfully kept the rain away. The rain held off until our return journey back to Canterbury! Location Figure 1 - Samphire Hoe seen from the air. The A20 coast road to Folkestone along the cliff top and Shakespeare cliff in the foreground. (Courtesy of Dover Echo) Samphire Hoe lies off the A20 between the ports of Dover and Folkestone. Specifically map reference 06’ 17.32N and 16’31.9” E. Access to the site is by a steeply descending tunnel dug through the chalk. This portal pierces Shakespeare cliff and serves as a permanent reminder of an attempt to drive a tunnel to France during the 70’s. The tunnel exit meets a ramp that runs to the base of Shakespeare Cliff and the Samphire Hoe plateau. Along the eastern edge of the plateau lies a 5 hectare industrial area housing several blue grey buildings. Fenced off and secure, they contain the ventilation and the cooling plant that pumps cooled fresh air into the channel tunnel. The Channel Tunnel is 50.5km long, and is the second longest tunnel in the world. The 37.4km midsection that runs under the sea, retains the record for the longest underwater tunnel in the world. Samphire road continues on between low hills and terminates at a vehicle car park with three small buildings. The site is owned by the Eurotunnel plc. , and is managed by the White Cliffs Countryside Partnership on their behalf. The Samphire Hoe Country Park is open daily, from 7 am until dusk. Figure 2 - Ready for the off! We assemble at the coach park and greet our guides With over 40 OUGS participants on this visit, we were split into two groups and having donned our hard hats were asked to wait by a grey van duly opened by the first of our guides - Melanie Wrigley. The Naming of Samphire Hoe The name Samphire Hoe was chosen as a result of a competition run by the local paper, the Dover Express. Familiar with Shakespeare’s play King Lear, Gillian Janaway, a teacher of English, entered the name Samphire Hoe for consideration by the judges with the following reasons. In act 4 scene 6 Edgar guides Gloucester, his now blinded father, to believe that he is on top of a steep cliff near Dover. Edgar speaks the following words: "There is a cliff whose high and bending head looks fearfully in the confined deep… The crows and choughs that wing the midway air scarce so gross as beetles; halfway down one that gathers samphire, dreadful trade!" At the time that William Shakespeare was writing King Lear he was said to have travelled regularly through Dover. The first cliff buttress on the West side of Dover is still known as Shakespeare’s cliff. The ‘samphire’ of the play is a yellow flowering rock plant with edible stems and leaves. It also is known as sea asparagus, sea fennel or crest marine (Crithmum maritimum). The plant that was being gathered still grows wild on the sea cliffs and rocky shores around Dover. Though scarce in this locality today, it can be sourced from Jersey or I am told, bought from fishmongers along the Kent coast. Rock samphire is also available as a salty, ‘aromatic’ pickle, rich in Vitamin C. It can be added fresh to a spring salad or boiled as a green vegetable. Figure 3 - Crithmum maritimum plant Figure 4 - Mrs. Gillian Janaway seated by rock samphire plant The Hoe part of Samphire Hoe means it is a promontory, a piece of land that juts out into the sea. We can instinctively feel that the name Samphire Hoe describes the location perfectly; a prosaic link that ties the present with this place’s past. Some local history The Railway; the origin of the Green Fall A rail road runs smoothly along the base of the cliffs. Built in 1843, this line hugs the coast between Folkestone and Dover. During the build, both Shakespeare and Abbots cliffs were tunnelled through. In between these tunnels the chalk had slumped and there had been several dangerous falls of rock. That section was blasted on the 26th of January using 150 barrels of gunpowder. After this big bang, the rock rubble was cleared away and the chalk was levelled to make the first promontory below the cliffs. This platform covered about 6 hectares, at a height of about 16m Above Ordanace Datum (AOD). A new piece of England, that was to be called the Green Fall had been created. The railway company built some houses for railway workers and during the 1940’s to the 1970’s an isolated community grew by the addition of a number of cottages and boat houses along the shore. The Green Fall could be accessed by the Shakespeare Cliff Halt private railway station or by descending the zigzag cliff path known as Aker’s steps west of Shakespeare cliff, or another zig zag path down Abbots Cliff, otherwise it was a boat trip or a long trudge along the shore. During the war years the MOD took over the area. Munitions were stored hereabouts and new coastal fortifications were constructed. Today the railway continues to maintain the link between Folkestone and Dover but Shakespeare Cliff Halt Station has fallen out of use. It lies near the entrance ramp, forelorn, dilapidated and in a state of disrepair. The Green Fall platform protected the cliffs and reduced the amount of erosion by the sea. In so doing it allowed plants to gain a foot hold. However, measurements indicate that weathering of the cliffs especially through freeze thaw continues and the force of gravity does the rest. The cliffs retreat inland. Measurements indicate that cliff faces retreat by as much as 0.1m per year. In the past, weathering and erosion have led to some spectacular cliff failures, with many slumps and falls. One such slump, to the west of the site, happened on 26 January 1988 and removed some 6000 cubic metres of chalk. Likewise, in 1912, 50,000 cubic metres of chalk fell into the sea. The latest recent rock fall in February of this year was on the western side of Abbots cliff and narrowly missed the railway line. Cracks at the top of the cliffs above Samphire Hoe are clearly visible from the ranger's office and could quite possibly be the next section of cliff to fail. About seven tonnes of rock will tumble down adding to the developing scree slope at the base of the cliff. Where there is little fore shore, erosion keeps the cliffs white by removing rock falls, never allowing the vegetation to gain a foot hold and the cliffs to green up. Tunnelling and mining the Green Fall - problems with politics and with local geology. The Green Fall provided an accessible working platform, a base from which mining and tunnelling enterprises were able to operate. Tunnelling The dream of a tunnel link to France began to take shape when Sir Edward Watkin a railway entrepreneur initiated a test tunnel in 1880. His miners used a mining machine invented by Colonel Beaumont MP but came to use an improved pneumatic boring machine patented by Captain Thomas English to drive the longest tunnel section under the sea. The 2040yds long tunnel passed through the lower grey chalk 100 ft below the sea and on a heading towards the admiralty pier in Dover. The technology worked and the break through just needed funding. However fear of invasion via a tunnel caught the mood of the public and an opposition to the tunnel grew. Politics of the time thwarted the drive and determination of Sir Watkin’s venture. Digging had to finally stop in 1889 when a high court injunction was served ending this affair. This tunnel became known as the Beaumont tunnel because it’s construction was wrongly attributed in ‘The Engineer’ magazine to have been excavated by the tunnelling machine patented by Colonel Beaumont MP. This tunnel was in fact driven by a more efficient tunnel excavator patented by a Captain English. However once the name entered the public domain it stuck. Mining at the Green Fall- (some mining geology) Successful collieries in Belgium and France indicted that coal measures should also be found in Kent. Lying the closest to the continent, Shakespeare Colliery also known as Dover Colliery was an obvious place to begin a venture and became the first coal mine to open in Kent. Kent Coalfields Syndicate Ltd. was formed in 1896, to take over a number of undercapitalized mining ventures. Bore holes had proved the presence of several seams of coal at depth, the best a 4ft seam at 2172ft. In June of 1896, the No1 pit (The Brady) was sunk. A 17ft diameter shaft was dug by miners and soon passed through the Chalk, Chalk Marl and Gault Clay strata. In October it reached the Lower Greensand 366ft. The Lower Greensand is an artesian aquifer and its waters flooded the pit. All further work was halted until pumps could be installed. Once this shaft was pumped out then work was able to continue. However the Brady pit had to be abandoned at a depth of 520 feet due to an influx of running sand that damaged the pump’s seals.