Mystery Object … This one has me beat

[SillyOldDufferModerator @sillyoldduffer]

Posted by ega on 13/09/2020 09:53:09:

Posted by Clive Hartland on 12/09/2020 14:11:14:

Re. bench marks. there are a lot of them around here in Medway. Chatham and Gillingham.

Interesting information about my own local area.

I had thought that benchmarks were shown on on the OS map but so far as I can see the nearest thing is the "triangulation" point.

Government arrow benchmarks are only shown on large scale OS maps, I think 6" to the mile and below.

Larger scale O/S maps also show 'spot heights', often at the centre of a road-junction. They're where the surveyor noted elevation but there isn't a physical marker. Smaller scale maps only show Trig Points, which were the major fixed triangulation points with height and position accurately recorded with a heavy concrete plinth intended to be permanent.

Lots of OS survey arrow benchmarks seen on walls etc are fakes. It was quite the fashion to copy them as a form of graffiti. Victorian yobs and other humorists, Real ones are well carved and shown on the map.

Many benchmarks have disappeared : in the screenshot above of an 1887 map, B.M.62⋅7 is on the end of a terrace demolished to extend the Gasworks, itself long gone.

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 13/09/2020 10:03:42:

Posted by ega on 13/09/2020 09:53:09:

|

You might find this interesting: **LINK**

https://www.ordnancesurvey.co.uk/benchmarks/

MichaelG.

…

.

… and I’ve just located this posting by Ordnance Survey: **LINK**

https://www.ordnancesurvey.co.uk/blog/2018/10/benchmarks-added-to-os-maps/

Note: Benchmarks and spot-heights were shown on earlier editions of OS maps … So, this appears to be reversion rather than innovation.

MichaelG.

[HopperParticipant @hopper]

Small world. My ancestors in Tasmania wore suits with those same arrows on them. (Heroic Irish patriots and freedom fighters all of them of course.)

[egaParticipant @ega]

MichaelG:

Thanks for those very informative benchmark links; the world has moved on.

Given that here are 500,000 of them mainly in built up areas it is, on reflection, hardly surprising that the smaller scale OS maps don't show them.

I am not now entirely clear as to whether your mystery object has been conclusively identified?

[Enough!Participant @enough]

Michael, I presume you tried a Google image search?

It didn't give me any results but you're better at that stuff than I am.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bandersnatch on 13/09/2020 17:33:12:

Michael, I presume you tried a Google image search?

It didn't give me any results but you're better at that stuff than I am.

.

The results were pitiful …

MichaelG.

[JasonBModerator @jasonb]

Michael, has your brother got a photo of the other side of the round disc? From what I can remember of Surveying at college there should be some engraving and a "dimple" sticking up in the middle but I may be thinking of trig points.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by ega on 13/09/2020 17:05:20:

[…]

I am not now entirely clear as to whether your mystery object has been conclusively identified?

.

Not to my satisfaction, I'm afraid : Hence the "Meanwhile … " comment, earlier

MichaelG.

Edited By Michael Gilligan on 13/09/2020 20:51:24

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 13/09/2020 20:15:38:

Michael, has your brother got a photo of the other side of the round disc?

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Not amongst the ones that he sent me … I will request one !

MichaelG.

[Speedy Builder5Participant @speedybuilder5]

Come on – Lets think this one through.

Its not precision

The construction is not made for strength

The holes are 2 different diameters

Its attached to something else, being bolted from the other side.

If it is supporting something round, its going to rattle about unless there is a rubber grommet or similar.

Its not "gas proof" as the surfaces aren't machined.

We don't have any dimensions – YET ?

Its not ex government

It was found on a playing field, but that may not be a clue

It has an identification number R2019 so what clue lies there ?

The thread form would give us a clue to age (BSF/BSW would be pre '60s ? Metric post '70s ??

Anything else to add to the list – I am sure there is.

Bob H

[Speedy Builder5Participant @speedybuilder5]

Lightning conductor item ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Speedy Builder5 on 13/09/2020 20:58:48:

Come on – Lets think this one through.

Its not precision

The construction is not made for strength

The holes are 2 different diameters

Its attached to something else, being bolted from the other side.

If it is supporting something round, its going to rattle about unless there is a rubber grommet or similar.

Its not "gas proof" as the surfaces aren't machined.

We don't have any dimensions – YET ?

Its not ex government

It was found on a playing field, but that may not be a clue

It has an identification number R2019 so what clue lies there ?

The thread form would give us a clue to age (BSF/BSW would be pre '60s ? Metric post '70s ??

Anything else to add to the list – I am sure there is.

Bob H

.

Bob … Please see my emboldening ^^^

1. I am using the information supplied to me

2. There is a plastic ruler in shot

3. When I asked my brother about the holes, he replied that they were plain, not threaded !

4. It was found in the 1960s

MichaelG.

Edited By Michael Gilligan on 13/09/2020 21:29:51

[Nigel Graham 2Participant @nigelgraham2]

If it is supporting something round, its going to rattle about unless there is a rubber grommet or similar.

Well, rattling might not have been a problem for whatever it held! The fittings might have been secured by their own threads and nuts, like pipe-fittings.

Its not ex government

We do not know that – not every component of every assembly in Govt. / Military service is stamped with a broad arrow or similar signifier.

It was found on a playing field, but that may not be a clue

Indeed, it could be simply a co-incidence; but one that along with the material and lack of machining makes me wonder if it was a bracket or similar fixed part of irrigation equipment.

Lightning conductor item ?

Feasible – is / was there a tall building with lightning-conductor in the vicinity?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by John McNamara on 12/09/2020 07:32:31:

.
Yes I know this is a segway… assuming the part is a survey mark […]

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It took me a while, John … but eventually I found this: **LINK**

https://en.wikipedia.org/wiki/Poeppel_Corner_Survey_Marker …which is the sort of thing I presume you mean.

I wasted a while, searching for segway, and finding electric scooters !

… Then it dawned upon me that you probably meant segue

MichaelG.

.

P.S. … I hope the move, and the shed-building, go well for you.

[Clive HartlandParticipant @clivehartland94829]

The web with two holes is the way it is held in the concrete block, it is a surveying marker for mounting some sort of surveying gear..

I have looked at all my sources but no match so it looks as if I will have to dig out my marker and take a photo.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Clive Hartland on 13/09/2020 22:13:33:

The web with two holes is the way it is held in the concrete block, it is a surveying marker for mounting some sort of surveying gear..

I have looked at all my sources but no match so it looks as if I will have to dig out my marker and take a photo.

.

Many thanks, Clive … Much appreciated

MichaelG.

[ShadowParticipant @shadow]

In my experience survey markers are called monumentation. I searched for Ordinance Survey Monumentation and found several pictures similar to the one I have included from the U.S.

[Mike E.Participant @mikee-85511]

It appears to be a datum point. I've seen these before embeded in cement on peaks of "named" mountains in California.

[Enough!Participant @enough]

Posted by Michael Gilligan on 13/09/2020 20:07:49:

Posted by Bandersnatch on 13/09/2020 17:33:12:

Michael, I presume you tried a Google image search?

It didn't give me any results but you're better at that stuff than I am..

The results were pitiful …

You mean I'm not as bad as I thought?

I have to say that my first take on it was of a simple location bracket for a couple of pipes running along a wall (bracket bolted to wall). Guess that's too simple eh?

[Speedy Builder5Participant @speedybuilder5]

From the first photo, them small holes look threaded ! They would be quite short for attaching anything heavy to. For my money, it would be cemented into something, the big holes providing a good bond to the cement/concrete etc. That would leave a round corrosion resistant plate on the surface to attach something light to. Lets assume that several of these were built into a large building's wall with the small holes horizontal and used to clamp the flat copper lightning conductor up the side of a building. If lightning struck, would the electricity try to exit the embedded bracket and blow the wall apart – probably. So for that, I would discount lightning protection.

Do petrol tankers have some sort of gauge stick that would be slide into a couple of these brackets ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 13/09/2020 20:53:25:

Posted by JasonB on 13/09/2020 20:15:38:

Michael, has your brother got a photo of the other side of the round disc?

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Not amongst the ones that he sent me … I will request one !

MichaelG.

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The plot thickens …
The item belongs to a friend of my brother, and is in Somerset [where he was visiting]

A photo has been requested, but meanwhile he can confirm that the underside was plain.

MichaelG.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, based on the photo with the rule, my thinking on dimensions roughly are; 2-1/2" where the rule is, 3" at the bulge, the disc 5" x 1/2" and overall height 7". The treaded holes in the disc, look to be 1/2" whit/UNC. This is my assumption just to get the size in prospective.

Regards Nick.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Speedy Builder5 on 14/09/2020 06:52:29:

From the first photo, them small holes look threaded !

.

Yes, I know …

I asked a question of a non-engineer, and shared his answer, but didn’t bother to labour the point.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Nicholas Farr on 14/09/2020 07:47:44:

Hi, based on the photo with the rule, my thinking on dimensions roughly are; 2-1/2" where the rule is, 3" at the bulge, the disc 5" x 1/2" and overall height 7". The treaded holes in the disc, look to be 1/2" whit/UNC. This is my assumption just to get the size in prospective.

Regards Nick.

.

Try working from this one, Nick

… There is still some perspective on it, but it’s good enough for a pretty rough casting:

.

I didn’t post it before, because I was hoping someone would simply recognise the thing

Which Clive appears to have done … [ but there again, so did Dave ]

MichaelG.

[JasonBModerator @jasonb]

Posted by Michael Gilligan on 14/09/2020 07:44:55:

The item belongs to a friend of my brother, and is in Somerset [where he was visiting]

That will make it a go-no go gauge for apples

I keep visualising something that had a WW2 bomb suspended from it but google did not turn anything up.

[Author]

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