Boulby Alum Tunnel

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Firstly if you intend to visit this site double check the tide tables before setting off,  to give yourself enough time to get there are back and avoid an air-sea rescue. The cliffs are also very unstable we heard numerous small rock falls and you don’t want to be underneath one.
There are numerous caves and what looks like the remains of a ships boiler on the the way around from Cowbar.
Boiler from a shipwreck ?
Boulby Cowbar Cave

The remains of the 17th Century Alum Tunnel were revealed by coastal erosion in the 1990s. Subsequent landslips and erosion are rapidly removing the tunnel at a rate of several feet per year, and its only a matter of time before a further landslips buries it, or its completely lost to the sea.

Boulby Alum Tunnel Entrance
Boulby Alum Tunnel Entrance
Boulby Alum Tunnel Entrance

The left-hand tunnel is now eroded nearly all the way back to what looks like a wall, it appear to be built against this wall, rather than actually being a blocked entrance although I cannot be certain if there is another tunnel behind or not. The outside edge of the inner course of bricks has been recently exposed to reveal symbols (perhaps masons marks, or maybe even something to indicate the order of construction ?) A row of bricks is also visible under the tunnel base.
Boulby Alum Tunnel Marked Bricks
Boulby Alum Tunnel Entrance
The right-hand tunnel is open and contains the remains of sleepers and rails as well as a large pile of washed in stones and debris.

Boulby Alum Tunnel Entrance

Boulby Alum Tunnel washed in stones

Boulby Alum Tunnel Rails

Boulby Alum Tunnel Entrance
Shortly after the pile of debris the tunnel opens into a slightly wider area with a large room off to the right hand side.

Boulby Alum Tunnel Ledge
Boulby Alum Tunnel Side Room

At this point there is a very large roof collapse with a chasm open in the cliff above, knowing the instability of the cliffs I though it wise not to progress any further, despite the tunnel looking in good condition further on.
Tracks can be seen leading off into the distance after the collapse, they would presumably at some point connect with a shaft from the Alum Works at the cliff top.

Boulby Alum Tunnel Collapse
Boulby Alum Tunnel

For anyone intending visiting I cannot say enough times, always remember this site is extremely dangerous.

15 thoughts on “Boulby Alum Tunnel

  1. I went inside this tunnel a few years ago soon after it first appeared and went to the end where the tunnel was filled with rubbish which had been dumped into the shaft over the years. As far as I can remember what little could be seen of the shaft suggested it was the same diameter as the width of the tunnel. The pile of crap was mainly mud and rocks but well littered with bits of old boots, bottles and throughly rusted cans; basically household and any other rubbish from years past.
    As my late father spent years excavating at the alum works he knew the owner of the alum house site at the top of the cliffs, Norman Barker, and was there one day when he had a JCB at work attempting to find the top of the shaft just on the west side of the remaining building. Although a large area was scraped off they failed to find the shaft top.
    An attempt to mine ironstone at Boulby in 1854 to supply the Seaham Ironworks intended to use this shaft and jetty for shipping it but came to nothing. The shaft was operated by a horse-gin and would have become disused when the alum works closed in 1871.
    When Boulby ironstone mine opened about 1903 the output went away by railway but the remaining building near the shaft was utilised as the pit stables.
    Finally, I have visited the foreshore here twice, each time by descending a fisherman’s path down the cliff which at the time had a lengthy and very elastic handrail made out of fireman’s hosepipes and railway wagon webbing!

  2. I am writing a childrens book involving hummersea harbour and the Alum works.. This tunnel, was it used to lower the alum down to the foreshore to be taken to the harbour and secondly does anyone know the names of any ships that used the harbour

  3. Some documents relating to ships were found in a farmhouse at Boulby Grange. These documents include the name of ships I think, as well as the name of the captain and what he expected to need for his trip in some cases. They are now at Whitby museum.

  4. The shaft and tunnel would be used not only for taking out the alum product but also for bringing in coal for fuel.
    Reg Firth at the Captain Cook museum in Staithes has details of the ships which supplied the works.

  5. I’ve also been to the end of this, probably 2004/2005. Also present are still the rails, sleepers and what look like some kind of iron drums for guiding the hauser that must have pulled the carts. The tunnel doesn’t follow a straight line and has a single bend in it. Its also whitewashed and I have some photos of 3 mens initials carved into the roof dated 1820.

  6. I visited the site last year having wanted to see the tunnel for some time. Someone had obviously been quite recently and a pile of iron artefacts(?) had been left out on the beach. I recovered a few: small iron wheel about 5″ dia, long iron coupling rod with pin at one end and eye at other. Presumably wheel from some sort of trolley though how it went on rails I don’t know, rod presumably from coupling same. I have these at home. Feel free to get in touch re above.

  7. Headed off over to the tunnel this morning – the entrances have eroded severely since you went, Chris – the left hand is now eroded back to the wall and the entrance to the main tunnel looks much different to the photos above. There doesn’t appear to have been any further deterioration in terms of the roof collapse though – I could pick my way over and head another thirty metres or so to where the tunnel took a slight right curve: at this point the wash-in and dumping down the shaft blocked the tunnel completely.
    Some photos:

  8. I have location of a (carefully) accessable jet mine on a cliff face a few miles away. Interesting to look inside, got some pics somewhere to post

  9. Also, the rail line Kettleness to Sandsend. Before they dug the tunnel, ( then the short one following the cliff fall) there was two exploratory tunnels dug across some points to plan a route. Anyone found these?

      • did you ever see the wonderful photo of the short tunnel construction at kettleness, taken from the east entrance
        and still showing the lost route on the cliff face?

  10. Also, do you have any info on the cruiser sent to recover a geman torpedo off runsick? the explosion killed all the crew but one (who was in sick bay). My gran dot taylor , daughter of joseph ‘laugh’ taylor, bowman of runswick lifeboat and uncle to robert patton, told me it blew all the windows out in the village.

  11. re the 17th century landslip, my gran said there was a wake at he time and all the villagers were in the one house, when the slip started she said they opened the door and the front step was a yard away from the door

  12. I remember my first visit, I think it would be around 1955, with my father and his friend and my father parked his car in a large flat area and we walked through a tunnel which exited in the harbour known as Port Mulgrave. As a 10 year old it was an intriguing adventure. I went back a few years ago and could find no sign of where we parked. was this the same place as the description?

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