GPO Cable Marker, age unknown, no Crown as predicted but carries government broad arrow.  This one still has one of the lead inserts which carried the distance measurement.

Enjoy jmb!

What location?

To avoid it being confused with Rutherglen items.

Perhaps the inserts with the numbers were officially removed.

Unlike proper OS benchmarks, fixed to immovable (unless there's an earthquake) substrates, many of these chiselled markers are found on objects such as milestones and border markers, and while these may be fixed (sort of, especially in the case of borders) they are far from stable. Like the GPO post above, these can move with the land, or further if a vehicle hits them.

Unofficial markers - by which I mean those not part of Ordnance Survey - would have been temporary, and used to provide reference points during site surveys and construction works. These would have provided reliable reference points for the life of the job, but would have been discarded once the work was complete.

See also thread on Crow's foot mark

Shore Road, Innellan.  There are several of them.  I think many of the lead markers were removed by small boys in the past.

By chance I spotted one today in the wall of a church.

Ah

That's one that can be recognised, an FBM or fixed bench mark. (I didn't have one to include here for comparison, so this one is very handy ).

The Rutherglen ones aren't even recorded by OS - somewhere near the start of this thread I've included their reply to a query.

(Found it, reply 10-22 above).

Actually, having read it again, I just realised they referred to the broad arrow but I didn't realise the significance back then

Still learning.

Not in Rutherglen of course but rather Dunoon and grabbed surreptitiously as it is outside a J. Arthur Rank.  I noticed it a few days ago and have never seen one anywhere else.

I suspect you will find Earth Rod covers around many commercial sites and certainly any radio towers.

MB

Yep...

I was surrounded by the things the other day when I happened to take a detour through some relatively recently built houses/flats.

They seemed to have gone mad with them, or maybe somebody dropped an extra 0 on the end of the quantity ordered and they just stuck them in to use them up. A different design to the above, round corners and raised squared on the cover, but there seemed to be one somewhere near the base of nearly every lamppost in the small estate.

Maybe they have a local problem with static?

You'll probably see quite a few now that you've realised they're there. Especially in and around newer builds, or if there have been recent street works.,

I think it is connected with requirements for regular electrical inspections, part of that is checking the earthing.  Each earthing point is opened up and measured separately.  

MB

Despite the weed in the pic I believe this is quite recent.  The concrete looked quite pristine when I first noticed it a couple of weeks ago.

The earth rod cover shown is a relatively modern one. They are surprisingly common although often well hidden or overgrown. Especially prevalant around hazardous/explosive areas buildings or radio/radar sites. Under the cover there is a copper earth rod or rods driven into the earth until a sufficiently low earth reading is obtained. Clamped to the rod are the copper earth tapes connected to the building for lightning protection.

If it's only earth tape or strapping, it will only be for earth bonding and static dissipation.

Lightning protection (we just happen to be running with this one on our Ardeer thread at the moment) will be by metal bus bars, as strapping/tape would just pop like a fuse under the first kiss of a lightning strike, and "protect" the lighting rod.

I'm not carrying any cameras at the moment, but since The Fox posted that first pic above, I seem to be coming across the things every time I go out, even newer than his as we have quite a few shopping centres and housing estates completed here in the past year or so.

Again, sorry there is no pic, which would have made the answer easier, but because I was thinking in "ground resistance mode", it took me a minute to realise why the first one I saw was marked SWL 5000 kg, while the next one upped the ante by having SWL 6000 kg marked on its cover.

The answer is obvious, and no doubt down to our old pal, Elfin Safety.

(If you're stuck, just ask, it's not a secret).

I can assure you that lightning protection is provided by copper tape. It will not pop (under most circumstances) like a fuse provided the lightning protection system has a sufficient number of paths and sufficiently low resistance value to earth (typically less than 5-10 ohms). My job involves the testing of such protection systems in explosive and hazardous areas.

The one I photographed seems to be a major earth to something in the building.  It certainly is not attached to a lightning conductor.  The company is based in Edinburgh and is known to be generous on the pension front.  I assumed it was some kind of protection for their computers.  I am sure  it hasn't been there all that long.  My attention was drawn to it a few weeks before the pic when I noticed the bright white concrete lid.

Ah, sorry, I did not register the use of the plural tapes in the original note, and fell into a mental picture of the earth bonding used around antenna bases in days gone by.

Of course, using multiple earthing distributed among thin(ner) straps will do the job just as well as the older system, and provides redundancy into the bargain.

The Edinburgh earth rod as seen by The Fox is part of the building's electrical supply and distribution system, and not related to lighting protection.

Although the ultimate operation and function of the earth rod is the same, where it is and what it does will vary by site and location, and it should be fairly obvious if it is for lighting protection or distribution.

Worth adding that the newer earth rod covers, with the SWL rating, appear to be plastic. I'm afraid they were in busy shopping areas though, so I didn't feel like attracting a collar-feeling session from security, so didn't start giving them a closer inspection.

I don't know if it was the same sort of cover, but I saw some workmen struggle with a nearby cover a few years back. Their proper hand tools wouldn't move it, so the brought over one of those tiny diggers - the ones that a man can just about fit inside - and used it to lift the cover by tying the tool to its arm...

Unfortunately, it remained jammed in place within its surrounding frame, which the little digger managed to lift with ease, together with all the block paving for about a metre around the thing, leaving a gaping hole where the original cover once only occupied a space of about two blocks. You're right - I didn't have a camera back then. It would have made a great video too.

I thought I had better keep the camera "warm" as it is months since I used it/them, and stuck it in my pocket when I headed to the shops this afternoon, on the last day of 2009.

As the pavements are all but non-gritted in the east end of Glasgow, I spent a lot of time looking at the ground, and happened to notice one of a series of surveyor's benchmarks I had spotted earlier this year, which are on the walls of some Victorian villas nearby. I only saw the one, although I recall that more were evident when I first spotted them. I'll have to go back in better weather - maybe even walk the whole road and see if there are many more to be caught one day.

Looks as if the dogs think these are target markers

It is actually somebody's garden, on the Hammy Road, but on the roadside.

I actually attribute the black corner to industrial era soot that wasn't cleaned off by a shoddy stonecleaning job on the sandstone - I think there are quite a few similar examples to be found.

Can you home in on the York Terrace you have in mind?

It seems to ring a bell, but I can't place it on any online maps, which don't seem to find any in Glasgow! (Assuming I'm not confusing the name with something similar of course).

Another mark made an appearance, obviously used as a seat by some gnomes that mugged some poor punter out celebrating Hogmanay.

There would have been a replaceble metal insert with the number of feet, but it's clearly long gone.

It looks like K9P is very corrosive on concrete.  Is that why the Red Road flats are to come down - too many dogs?