Friday, 14 February 2020

Federation Road - Tthe Bostall Estate Chalk Mine


A recent planning application in Federation Road has highlighted one of Greenwich's most- difficult-to-see industrial sites. The following text is from an article by Rod LeGear (reproduced with his permission)

In 1899 the Royal Arsenal Co-operative Society embarked on a large building project, a venture very different from that of its modern retail activities. A small town/settlement was to be built suitable for 'the industrial classes'. The Bostall Estate was constructed by the R.A.C.S. Works Department which moved from the Society's headquarters in Woolwich to the site, which was to the south-west of Abbey Wood station and north of Bostall Heath. A feature of the building works was the centralisation of the various construction trades in an area of workshops where much of the work could be pre-fabricated. Items such as doors, window names, etc., as well as bricks and other building materials, were transported from the workshops to all parts of the site on light tram lines radiating from the work area which was to the south of the construction site. A total of 4 miles of tram lines were put down and at least 50 tip wagons ran on them.

The temporary site for the works department was chosen for its position on the estate. As the site was uphill from the main building area gravity could be utilised when transporting materials on the tramways. It was also chosen for the natural resources available on site - sand, ballast, chalk, and water

This area of intense activity at the turn of the century is now occupied by the Co-operative Woods camp site on the south side of Federation Road. The only reminders of its industrial past is Federation Hall. which was the works dining hall and, hidden 60 feet below ground, nearly 2,000 ft of manmade caves - the Bostall Estate chalk mine.

The mine was dug to provide chalk for the building operations on the new estate. Most of the chalk was burnt in a kiln to give lime which was suitable for internal plasterwork. Unburnt, the chalk was used as a foundation for the estate roads.

The 8ft diameter shaft was sunk in January 1900 in a corner of the works area near to the mortar mill and lime kiln. Four main headings were driven from the base of the shaft to commence mining operations. The floor of the mine was on or just below the water table as the mine was also used to obtain water for the mixing of mortar in the manufacturing processes

The mine was drained by pumps driven by a 16 h.p. surface engine. This engine, made by Marshal & Sons of Gainsborough, also powered the mine's winding hoist as well as a dynamo which provided electric light in the mine. This was an unusual feature as most mines of this period were lit by candle or oil lamps. The hard worked engine also provided motive power to the workshop machines via a system of shaft drives.

In the first full year of operation four men worked underground cutting out the chalk with picks and wheeling the excavated material to the shaft bottom in barrows. Two men were employed on the surface to unload the chalk from the tub and barrow it to either the lime kiln or to a nearby dump for collection by the road building gangs. By 1902 the workforce had increased to six men underground and four on the surface. From 1903 until 1906 the figures were five below and two above ground. 

After 1906 the mine had ceased operation. For the first two years of its life the mine was recorded in the Inspector of Mines Reports as 'Suffolk Place Mine '. From 1902 it was shown as 'Bostall Estate Mine '. Originally the mine was named after the land on which it was situated - Suffolk Place Farm - one of the two parcels of land that made up the development. The committee of the _ Society however, decided to call the building venture after the original fame bought in 1887. This dual naming of the mine has led to some historians searching in vain for another mine which does exist.

In 1914 the mine was converted into an air raid shelter by the addition of a sloping entrance by the side of Co-operative Hall (now called Federation Hall). The underground tunnels remained accessible up to the 1960's when it was still possible to crawl into the rubbish filled entrance. Harry Pearman of the Chelsea Speleological Society entered by this method in 1960 and produced a quick survey. Some time after the entrance was completely filled following fears that children, who were known to 'explore ' and play in the caves, could become lost or injured.

The next visit to the mine was in 1967 when, with the kind permission of the R.A.C.S. and the local authority, a small group of mining archaeologists, led by the writer, made an examination of the underground galleries. The strong grill sealing the top of the shaft was removed by workmen from the London Borough of Greenwich (the principle lessee of the site) in order to gain access

In the early days of building work on the new estate an al-fresco concert was held each summer in the nearby woods. Visitors were shown around the new houses and workshops, and adventurous souls were lowered down the shaft in the cage/tub and taken on a conducted tour of the mine.  

In 1967 the shaft was descended using strong lightweight flexible wire 'caving ' ladders and associated safety equipment. When the mine was to be converted to a shelter a detailed plan of the underground galleries was made by Howard Humphreys & Sons of Westminster. During the 1967 visit the plan was checked and a new survey was plotted to the same scale. Very few differences were found, the most significant being that the sloping entrance was now filled and inaccessible. Another was the appearance of a small excavation at the end of a side passage off of the main southern gallery. This consisted of two poorly cut upwardly inclined tunnels which joined after a few feet. It is probable that this relatively modern piece of mining had been undertaken by adventurous youths at a time prior to the closure of the sloping entrance.

The mine was found to be in excellent condition with no roof falls or sign of stress in the wall observed. The galleries average 10ft  wide and 18 ft high with an arched roof which gave a mechanically strong cross section. Chalk is fairly easy to mine and is usually quite stable so it is not necessary to use props as long as care is taken on the roof sections. The junctions of galleries are also cut with great care to ensure that the loads are spread correctly. The highest galleries are to the south of the shaft where the main development of the mine took place. The adits are 20ft high in this section. Only three galleries were dug to the north of the shaft and they are only 11ft high. In this part of the mine the depth of the roof below the surface is only about 17ft. The excavators wisely did not extend the mine further in this direction as the surface slopes down to the north and cover would have been decreased to a point when the risk of subsidence would become acute.

The mine proceeded forward in a series of steps or benches, the miners cutting away their working platform as the adit was extended. A number of those benches could be seen in the Bostall Estate mine. Such working benches can be seen in any chalk mine. But their presence in the chalk workings at Chiselhurst have lead to the rather quaint theory that they are 'Druid's Altars' The final layout of the mine developed from the four original galleries radiating from the shaft. From these main driveways other adits were cut at right-angles to be joined by cross passages which created large pillars of chalk to support the ground above. From a careful study of the underground galleries and the pick marks left by the miners tools it is possible to re- construct the probable development sequence of the mine. 

The last section of the mine to be worked was an extension to the south when a farther 1 80ft of passages were excavated in 1906, the last year of operation.

The final addition to the mine was made in 1914 when the drift entrance was the side of Federation Hall so that underground tunnels could be used as an air-raid shelter. The sloping tunnel from the surface was intercepted by another dug from the main east driveway to create the shelter entrance. Although the water table had dropped since the mine was abandoned, it was found necessary to put boards and gravel on the floor as parts of the mine were wet. Harry Pearman noted several inches of scummy water, over much of floor during his visit in 1960. In 1967 no water was present although a long period of dry weather had proceeded the date of the investigation. By 1939 parts of the entrance drift had fallen in and it was declared unsafe. For this reason, despite vigorous protests from local residents, the mine was not used as a shelter in the Second World War.

Upon completion of the two day investigation of the mine in 1967 the shaft was re-sealed and made safe, the underground galleries once again quiet and dark, and a silent reminder of the busy industry that existed on the surface at the turn of the century.

This piece first appeared in GIHS Newsletter November 2005


Kate said...

Thank you so much for taking the time to write about this it’s incredibly interesting do you think they’ll ever open it up to the public like they have done for Chislehurst caves.

Kate said...

Thank you so much for taking the time to write about this it’s incredibly interesting do you think they’ll ever open it up to the public like they have done for Chislehurst caves.