On the way back to the airport from Penrith last week, I noticed, as I was sitting in a traffic jam, several "Buried Structure" signs, with "M6" and some other number on them. I don't ever remember seeing them before, and I travel that way regularly (although possibly I just haven't been in a jam in the right place before!) Does anyone know when they appeared, and what is buried?

I'd imagine they'd be culverts, cattle creeps and the like.
All these structures will have an asset reference, as they will need to be inspected and maintained. So signing would make life easier.
For the time being, I still need to ask...where?

Yes, exactly where would've been a good thing for me to say in the first place. Between J32 and Forton services.

Could be something like an underground pipeline.

I was talking to a pipeline surveyor the other day - he told me that those little posts with what look like small orange pitched roofs on them mark locations for underground pipework (I'd been wondering what they were for years).

Apparently it's so important that, say, high pressure gas pipes aren't disturbed in any way that these are overflown by specialist surveyors in helicopters every fortnight in order to ensure that no construction/agricultural work is going on that could threaten their integrity.

Ill confirm this, The orange tops are to give visibility to the air. AFAIK they are always referencing gas pipelines, though am willing to be proved wrong.

Not the bridge works by any chance?

I crawled along for about 45 mins between Broughton and the works on Saturday going North and the Southbound M6 was backed up to past J33 with the local radio saying it was taking traffic an hour plus to get through.

In a morning though during the commute it is fine, we get along at 50 no bother (apart from the wagon drivers who insist on speeding....todays worst offender a driver from New Forest Caravans who sped past me with 3 huge caravans on his back), but Saturday was a right pain.

They are also used by the GPSS.

This pageidentifies the different types of marker.

MB

I've dragged this back up because I had a better look on the way back down today. The signs were (for example):

Buried Structure
M6//370.00/Q/2

The M6 is obviously the motorway, the 370.00 is the location on the motorway (agrees with the markers), but I don't know about the Q or the 2. All the ones I saw had the Q, some had the 1 or 2, and others had no final number. I think they all had a double slash in them. So, that's most of the sign deciphered... One was definitely a culvert, the other looked like an ordinary bridge (but was just to the side, so could've referred to something else), and a third was next to a grating.

All to do with SMIS (the HA's structures asset management system) and Structures Keys which are the HA's unique identifier for each structure.
I normally have a consultant to deal with this for me so IIRC the Q will be a type identifier e.g. buried culvert and the number will be the instance so there may be no number, 1, 2 or more structures of the same type at the same location.
Have a look here for the information needed when a structure is constructed. This information is all kept in a record against the structure key number.

THe Linkswood to Leuchars GPSS one is a bit wrong, Linkswood is in the right place, but Leuchars seems to be down by Elie!

Their are a lot more pipelines that what is shown on Linewatch...

The BP Forties - Cruden Bay to Kinneil (Grangemouth)
Theres also a Shell one which runs nearby the whole route.
Ineos also have an ethylene line in Fife.
And theres obviously the high pressure National Grid Gas mains

Digging near these isn't a good idea

There's one of those "buried structures" signs on the eastbound M55 near the Kirkham junction, it might be connected to a main gas pipeline which runs around there.

I don't if this is the 'original' M6 buried structure sign:

http://www.flickr.com/photos/sidelong/7670598462/

The Lancaster Canal is culverted at this point:

http://www.flickr.com/photos/sidelong/7 ... otostream/

Dave

I remember the M65 having "interceptor" signs like these but those have now changed to the more standard "PCD" signs.