Construction of Gillingham (Kent) tunnel

[faa77]

There is a tunnel immediately beyond Gillingham (Kent) station, towards Chatham/London. I'd like to find information how this tunnel was constructed. Given the keywords involved "Gillingham" + "tunnel" I get a lot of spurious results from Google, particularly related to nearby road tunnels and other chaff.

 

Is there a better way of finding how this tunnel was constructed? Plans/diagrams etc? The line was opened 1858 so I believe the tunnel was dug shortly before.

 

Any suggestions would be welcome.

 

Any persons who are intimately-acquainted with this particular tunnel, please send me a private message.

 

Thanks in advance,

[Mick Bonwick]

Are you referring to the tunnel under Balmoral Road and the station, or the one further towards Chatham that goes under The Lines and comes out onto the viaduct? 

[Mike Storey]

You might find this of some initial help, in explaining the route taken and the reasons for the various elevations.

 

https://books.google.fr/books?id=iLg5AQAAMAAJ&pg=PA336&lpg=PA336&dq=brompton+railway+tunnel+kent&source=bl&ots=UyOGuP6QFR&sig=ACfU3U2bJlnfxao__7wATir-LdaTpODOIg&hl=en&sa=X&ved=2ahUKEwiX64eRjNLiAhXBz4UKHRitC2IQ6AEwDXoECAkQAQ#v=onepage&q=brompton railway tunnel kent&f=false

 

[Andy Hayter]

2 hours ago, Mick Bonwick said:

Are you referring to the tunnel under Balmoral Road and the station, or the one further towards Chatham that goes under The Lines and comes out onto the viaduct? 

 

The former is hardly a tunnel - just a road bridge with the station building and a narrow drive in.  Not even wide enough to allow a taxi stand which was round the corner to the North of the station.

[Mick Bonwick]

3 hours ago, Andy Hayter said:

 

The former is hardly a tunnel - just a road bridge with the station building and a narrow drive in.  Not even wide enough to allow a taxi stand which was round the corner to the North of the station.

 

Must be the latter, then.

[Lyddrail]

The tunnel under the station building is called "Gillingham Tunnel" 897 yards long, next is "Chatham Tunnel" 297 yards.

Cheers.

 

Paul.

[Andy Hayter]

Paul

 

That does not tally with my recollections from admitted many years ago, nor with this picture taken from the platform, under te station and towards Chatham tunnel.

 

https://uk.images.search.yahoo.com/search/images;_ylt=AwrP4k1M8fdcNn0A8UZLBQx.;_ylu=X3oDMTByZmVxM3N0BGNvbG8DaXIyBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=Gillingham+tunnel&fr=yfp-t#id=4&iurl=http%3A%2F%2Fwww.kentrail.org.uk%2FGillingham_2004_2.jpg&action=click

 

There is a Gillingham tunnel of around that length, but it is the other Gillingham.  The one in Dorset.

[JohnGi]

I happen to live in Gillingham. The book linked to by Mike Storey is very interesting, and I recognise several of the place names in the engineer's evidence. 

 

It predates the line's actual construction by several years, and it seems to be describing a proposed route along the Chatham waterfront, approaching within 100 yards of Gun Wharf, and tunnelling under the Great Lines (called the Chatham Lines by the engineer in the book), at a point which just avoids the fortifications and the military cemetery. I assume the fortification referred to is Fort Amherst. I'm not sure about the cemetery, it might be near the back of the old Chatham town hall. The competing proposal seemed to tunnel under the "citadel" - also Fort Amherst? Both these lines would have been some way to the north of the current line. There must have been some reason why the current alignment, which has two extra tunnels - Chatham tunnel as mentioned above - and a further tunnel under Fort Pitt was chosen instead, although Gillingham tunnel (897 yards) is slightly shorter than the tunnel (1000 yards) proposed in the extract.

 

EDIT:

 

Just seen Andy Hayter's comment.

 

Starting at Gillingham

 

Under Balmoral Road

In cutting

Enters tunnel near Canterbury Road - this must be Gillingham tunnel referred to by Paul. 

Under Great Lines.

Exits near A2 in Chatham

Crosses A2 at Luton Arches.

Runs to south of Chatham town centre

Tunnels under Westmount Avenue - this must be Chatham tunnel

Chatham station.

Edited June 5, 2019 by JohnGi

[faa77]

9 hours ago, Mick Bonwick said:

Are you referring to the tunnel under Balmoral Road and the station, or the one further towards Chatham that goes under The Lines and comes out onto the viaduct? 

 

One under the Lines

Edited June 5, 2019 by faa77

[faa77]

8 hours ago, Mike Storey said:

You might find this of some initial help, in explaining the route taken and the reasons for the various elevations.

 

https://books.google.fr/books?id=iLg5AQAAMAAJ&pg=PA336&lpg=PA336&dq=brompton+railway+tunnel+kent&source=bl&ots=UyOGuP6QFR&sig=ACfU3U2bJlnfxao__7wATir-LdaTpODOIg&hl=en&sa=X&ved=2ahUKEwiX64eRjNLiAhXBz4UKHRitC2IQ6AEwDXoECAkQAQ#v=onepage&q=brompton railway tunnel kent&f=false

 

 

Hi Mike, forgive me if i have missed something, but those minutes seem to discuss more about the original, discarded route under/near Fort Amhurst, rather than the existing route over Luton arches?

 

Do minutes exist for the construction requirements after they chose the present day route?

Edited June 5, 2019 by faa77

[Lyddrail]

Andy,

I took the info off a NR track/signalling diagram, which didn't show bridges, hence my mistake. I listed the first tunnel. The road bridge is described as Jubilee/Victoria Rd no. 171 on another NR diagram.

Cheers.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Mike Storey]

3 hours ago, faa77 said:

 

Hi Mike, forgive me if i have missed something, but those minutes seem to discuss more about the original, discarded route under/near Fort Amhurst, rather than the existing route over Luton arches?

 

Do minutes exist for the construction requirements after they chose the present day route?

 

Best I could find in a brief search, after many years dipping into this (after living near the Luton Arches for some time during my first serious railway career!).

 

[Mike Storey]

5 hours ago, Andy Hayter said:

Paul

 

That does not tally with my recollections from admitted many years ago, nor with this picture taken from the platform, under te station and towards Chatham tunnel.

 

https://uk.images.search.yahoo.com/search/images;_ylt=AwrP4k1M8fdcNn0A8UZLBQx.;_ylu=X3oDMTByZmVxM3N0BGNvbG8DaXIyBHBvcwMxBHZ0aWQDBHNlYwNzYw--?p=Gillingham+tunnel&fr=yfp-t#id=4&iurl=http%3A%2F%2Fwww.kentrail.org.uk%2FGillingham_2004_2.jpg&action=click

 

There is a Gillingham tunnel of around that length, but it is the other Gillingham.  The one in Dorset.

 

Where is the Gillingham Dorset tunnel Andy? I went there many times in a previous life, but do not remember any lengthy tunnels near Gillingham. The current Gillingham (Kent) tunnel, whilst not next to the station, is 897 yards, followed by the 100 yard Chatham tunnel, after the arches.

 

[a98087]

Gillingham Dorset  tunnel is at buckhorn western, 

[Mike Storey]

19 minutes ago, a98087 said:

Gillingham Dorset  tunnel is at buckhorn western, 

 

Thanks - I see it. About 2000 yards west. No wonder I never noticed it!

 

[Nearholmer]

Does the original question stem from the great debate/argument here? http://www.kenthistoryforum.co.uk/index.php?topic=1254.0

 

Or, is it a civil engineering question, along the lines “how were tunnels through chalk (it is chalk isn’t it?) dug in the 1850s?”.

[faa77]

4 hours ago, Nearholmer said:

Does the original question stem from the great debate/argument here? http://www.kenthistoryforum.co.uk/index.php?topic=1254.0

 

Or, is it a civil engineering question, along the lines “how were tunnels through chalk (it is chalk isn’t it?) dug in the 1850s?”.

 

The question is related to the KHF thread, but not entirely...... 

 

I have a photo of a tunnel (not at Luton Arches, but nearby and not the air ventilation shaft) and someone working at Amhurst said this tunnel was dug by the railway to remove spoil.

 

I am trying to ascertain whether they did dig a second tunnel to construct Gillingham tunnel.

Edited June 6, 2019 by faa77

[Nearholmer]

The usual way to dig a tunnel was from the two ends, and by sinking intermediate shafts, which then became ventilation shafts for the finished tunnel, and digging outwards in each direction from the foot of each shaft.

 

Looking at old maps, your tunnel has one air shaft near the middle, which would give four "working faces" (two from the shaft, plus one at each end), which seems about right for its length.

 

The only curiosity about the tunnel that I can spot on maps is that the eastern third of it runs below what might be called a "sterilised strip" of land, on which nothing seems to have been built. This is very unusual, and implies to me that either it was built "cut and cover" (dig a trench, build a tunnel, bury it), that the ground was very unstable, and/or the tunnel very shallow, and that perhaps the railway company retained ownership of the land above the tunnel, perhaps with a view to opening it out to become a cutting if it all proved utterly unstable.

 

Digging an adit to allow spoil to be transported out would be a fairly unusual approach, but I think it has been done in a few places where pre-existing development over the tunnel has made it impractical to extract spoil through shafts - I have a dim recollection that parts of both the City & South London Railway and the GPO Tube had spoil-extraction adits. But, if that was done at Gillingham, the old maps hold no clues that I can spot.

[JohnGi]

1 hour ago, Nearholmer said:

The only curiosity about the tunnel that I can spot on maps is that the eastern third of it runs below what might be called a "sterilised strip" of land, on which nothing seems to have been built. This is very unusual, and implies to me that either it was built "cut and cover" (dig a trench, build a tunnel, bury it), that the ground was very unstable, and/or the tunnel very shallow, and that perhaps the railway company retained ownership of the land above the tunnel, perhaps with a view to opening it out to become a cutting if it all proved utterly unstable.

 

You probably mean the western third. That 'sterilised' land is part of the Great Lines which was military property. It probably avoided housing development for that reason. As you probably know this area is part of the North Downs (chalk) and there are often steep changes in elevation. Cut and cover is unlikely, the Lines are much higher than the railway - I'd tell you how much but I can't find my OS map at the moment.

 

 

[Nearholmer]

No, I mean what I said: the eastern third.

 

If you look at old 25" maps, it's very clear. Streets of houses, with a broad gap through them , below which runs the tunnel.

 

Its worth looking at this https://en-gb.topographic-map.com/maps/b9/England/ to see the exact topography. Its far easier than trying to read detail from an OS map.

 

Looking closely, I think that the tunnel is quite shallow at the eastern end.

 

 

Edited June 6, 2019 by Nearholmer

[JohnGi]

Nearholmer, Thanks for reply, I see exactly what you mean.

 

Here is a google satellite view. I see a tarmac area with parked cars on the line of the tunnel breaking the line of the streets and houses - this is Medway Used Vans - which fits in with what you said about sterilised land. Further south on a similar, but slightly different,  alignment there is a row of lock up garages, a social club, and an diagonal alley way which continues as far as Marlborough Road.

 

 

Here is 1898 OS map. 

 

 

Here is 1907. They're starting to build houses over the tunnel in Marlborough Road and College Avenue - the air shaft is in someone's back garden.

 

 

 

 

[Nearholmer]

What we need is a Network Rail structural engineer familiar with the area to tell us why the railway might have kept this section free of over-development. 

 

My guess is still shallow cover in unstable ground. Chalk is sometimes a very solid mass, but in other places its like large clumps, with fissures in between, which can become very unstable, especially if its near a spring-line.

 

I would be that the "stone" shown in this area had something engraved on it about ownership, unless, random further thought, the area had been a burial-site and was protected from development for that reason ........ needs even older maps and members of the KHF. One of my brothers lives not far from there, so I'll see if I can get him on the case!

 

PS: There is a very nice 6" map, published 1869, on the NLS site, which shows the area when development of housing at the eastern end of the tunnel had barely started, and labels Gillinham station by its initial name of 'New Brompton'.

 

PPS: This photo shows the van-hire yard on the "sterilised strip" https://www.geograph.org.uk/photo/1403864.

Edited June 7, 2019 by Nearholmer

[JohnGi]

On this 1856 map Gillingham is centred around St Mary's Church, and is larger than New Brompton. On the 1869 map New Brompton is larger than Gillingham. The railway station would be at the southern edge of the of orchards? between the two places. The football team also used to be called New Brompton - the changed their name in 1912.

 

 

PS rather unusually this map shows Chatham dockyard rather than leaving a blank space.

Edited June 7, 2019 by JohnGi

[Nearholmer]

Not directly relevant, but a very interesting insight to the early working of the railway in this area https://www.railwaysarchive.co.uk/documents/BoT_ChathamHillTunnel1862.pdf

[faa77]

I am sure I did read somewhere, years ago, the Eastern entrance was built using cut & cover.