Funny Castle Things straddling M45

[caro_]

Hi

Can anyone tell me what these are? There are a long line of crenolated towers - some large, some small - which traverse the countryside near where the M45 joins the M1. They also straddle one of the A roads (I think A428?)

Have driven past them for years and always wanted to know. Perhaps they are air holes for sewers or something equally boring!

[Fitzer]

I believe they are ventilation towers for a tunnel on the Grand Union canal, looking at the aerial photos on Multimap the canal certainly goes into a tunnel around there.

[Fitzer]

Just looked a bit more at Multimap and there are several circular items shown on the map above a railway tunnel there so might be those.

[Cathyhuns]

They are ventilation towers for the Blisworth tunnel on the Grand Union Canal. As it took sometime to get through the tunnel - it was 1.75 miles long and originally boats were moved through it by legging - ie lying on your back and using your legs to push the boat forward - the tunnel had to be ventilated.

Victorian rail tunnels were not usually provided with ventilation as the trains moved through quickly enough, other than in cases where steam vents had to be allowed for as on the London Undergound.

[mushroom25]

Blisworth canal tunnel is south of M1 J15a, which puts it some way away from the M45 & surrounding area.

The air shafts astride the M45 belong to Kilsby rail tunnel, on the West Coast Main Line; there are a lot of small ones and 2 huge ones, which are visible from the train as you pass through, as 2 large voids.

Just north of the M45 turn-off is another shaft on the right hand side of the motorway, this belongs to Watford Lodge tunnel, on the Northampton-Rugby line.

[caro_]

Thanks guys - I must drive past the Blisworth ones too fairly frequently and the Watford Lodge one too. Funnily enough I just thought they were all part of the same system and hadn't really registered that between Klisby and Bilsworth lies about 30 miles of land! Shows how worrying autopilot can be.

Thanks again

[sddsddean]

Just to confirm (as I live about 4 miles from them) they are the 3 main vents to Kilsby Railway tunnel designed by Robert Stephenson. There are 5 other 'ordinary' vent shafts. The shafts are just over 50 feet diameter. The tunnel is on the London-Birmingham main line, whilst the Watford tunnel is on the Roade-Northampton-Rugby loop. I think the main confusion as to the mode of transport in the area, is that 4 main routes use the Watford Gap (which is a geographical place, a gap in a range of hills) on their way North - South. At one point near Long Buckby Wharf, you have the old Roman Road (now the A5), M1, Grand Junction (now Grand Union) canal and the London Birmingham mainline within 400 yards of each other.

[caro_]

So, Sddsddean, when I see all these towers they are a lot closer together than I thought in my last post. That is a relief as I was beginning to think my 50 mile each way daily commute from Solihull to Northampton eas being done completely on autopilot and I had no idea where I was!

Thanks for giving a succinct answer - at least when I go past them tomorrow the problem will be solved. Not sewers then.........

[sddsddean]

I'm just wondering caro_ what you mean by 'all those towers'. Don't know which way you come to N'pton, but if you come south down the M1, as you go up the hill from J18 there is a vent shaft on the left hand side of the M'way. This is for Crick tunnel which is on the N'pton loop line. Also have you noticed that 8 of the Hillmorton radio masts have been demolished? There are only 4 left and I know a bloke who used to work on them. They are 835 feet high and each has a lift up the centre. Officially they were used by the Post Office for International Telegrams, but I have heard their real use was for low frequency communication to submerged nuclear submarines! The aerial array would certainly have been big enough.