Forum Topic

Ordnance Survey benchmarks

https://www.youtube.com/watch?v=sWxXyR4ifbkI came across an interesting youtube video (3 mins) about 19th century 'benchmarks' used by Ordnance Survey to calculate elevation. Has anyone spotted any in Putney?

Adam Tripp ● 27d12 Comments

I’ve checked out a couple near me. No sign of them. I think if people rebuild or remove a wall the benchmark will disappear. I’m yet to find a survivor but I’ll keep looking.

Jonathan Callaway ● 25d

David, are benchmarks replaced when an old building is demolished? thx

Adam Tripp ● 26d

OS benchmarks are located at approx every 250 metres in all built up areas of the UK.Locations are on all 1:1250 scale OS plans.They are particularly important in flood defence schemes.There is a good example on the wall halfway over the  bridge.Retired OS surveyor and Putney resident since 1977.Retired Ordnance Surveyor and Putney resident for 50 years

David Wilson ● 26d

Some that are on the 'Historic OS 1896 London' Map still appear on the interactivemaps.https://www.wandsworth.gov.uk/planning-and-building-control/conservation-and-urban-design/borough-history/historic-maps-of-wandsworth/

Ed Robinson ● 27d

excellent, thx JC, I didn't expect them to be so common

Adam Tripp ● 27d

Thank you, Jonathan Calloway - wow, what a lot there are!!!

Judy Allen ● 27d

Check out your nearest ones here: https://interactivemaps.uk/os-benchmark-archive/#16.98/51.460557/-0.230046

Jonathan Callaway ● 27d

Thanks, Philippa. I was up early this morning after another late night and my brain was still waking up! 

Michael Ixer ● 27d

Michael  I think perhaps you meant 'hikers' - because I've never heard of hickers? I did map reading around Winchester when I was about 10 and at boarding school.  I found it fascinating and still do - and a great way and reason to get out of the classroom and learn.  I too guess kids nowadays don't do this - and yes, rely on satnav apps on a phone which won't tell them about a lot of things about the landscape around them.

Philippa Bond ● 27d

Fascinating!👍Thanks for the link Adam. xx

Sue Hammond ● 27d

Wow, thanks. I'd forgotten all about those. I remember part of my geography 'O' level was OS map reading and - although not part of the course - these got mentioned. I bet with the advent of satnavs map reading is becoming a lost skill except for hardened hickers? (Why did predictive text try to change that to hackers!?)

Michael Ixer ● 27d

That's really interesting.  I've never consciously noticed any in Putney, but the symbol does seem vaguely familiar.  I shall look out for them now.

Judy Allen ● 27d