The LNER Encyclopedia

Bryan wrote:

R. pike wrote:The concrete items in the four foot are alignment markers. They make very nice supports for garden railways..

Normally only found in the 6ft on double track and in the 4ft of single lines.
So why are they doubled up here?
Spacing seems a bit closer than normal as well.

I agree they are rather close to give a useful and measurable increment of cant. Any curvature here must be very slight though i can see a need for more cant on a faster road hence they are doubled up.

Monument markers were not intended to define the changing cant through a transition.
They mark the alignment for the line concerned, either on regular curve or straight at regular intervals, generally about a chain apart (22yd). Those in the photo are approx 40ft apart after a rough sleeper count.
The lead plate in the top would indicate offset to Running edge of relevant track and regular cant would also be stamped in.
Cant plates would be fixed to the sleepers to define the specific cant for each track, defining top and bottom of transition and indicating the spot cant within a transition at 5mm intervals (or 1/4" in imperial) usually fixed to the sleeper on the 4ft side of the high rail baseplate.
These plates varied from Cast Iron nailed to a wooden sleeper to a small aluminium square glued to a concrete sleeper. With paint marking added later and now superceded by preprinted plastic plates either glued or power nailed to any sleeper type.

http://www.flickr.com/photos/32297024@N08/4278364709/

Shows an uprooted alignment marker of the type in the shot at Greenwood. The holes in the top had wooden plugs and little round numbers with spikes on the back were hammered in to give the appropriate measurement. As i said earlier they make very nice supports for my garden railway.

I have also seen them used to make garden retaining walls and boundary markers for gardens with lengths of chain strung between them.

I also know that Ballast cleaners have a strong dislike for them.

This was on the up slow at Greenwood during renewals a couple of years back..

http://www.youtube.com/user/LNERGE#p/u/11/epwic-J6rFM

Luckily the troughing route it found was from the 1955 widening..

Bryan wrote: " Monument markers were not intended to define the changing cant through a transition.
They mark the alignment for the line concerned, either on regular curve or straight at regular intervals, generally about a chain apart (22yd). Those in the photo are approx 40ft apart after a rough sleeper count. " ....

I wonder if they were being extra careful to get an alignment exactly right.

The two 9F pics taken there on the Down Fast, post-quadrupling, including that of 92141, look to be only (very roughly) about 50 yards before Hadley South Tunnel portal.
As the new 2-track tunnel bore for the quadrupling at this point appears to be parallel with the original 2-track bore, with which the Down Main and Up/Main Fast had previously lined up exactly [flanked, from the south as far as Greenwood, by the Down Goods and Up Slow], the new alignment to take the down lines through the new bore involved something of a reverse curve, with its latter part a bit of a dog-leg (comparatively-speaking, in track terms).

So I would think the pictured 9F is probably on that sharpest part, and so perhaps the closely-spaced markers were involved in getting a critical curve spot on?