| OSBM
BOLT "OSBM Bolt" is quite large - an inch or
two in diameter (25 - 50mm) (sizes vary), with letters "O S B M" and an arrow engraved into the Bolt itself.(Some of the older ones have no markings.) |
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 1GL BOLT or PA BOLT is a cut
mark with a small bolt. The bolt can be next to the cut benchmark or in the apex. |
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| CUT BENCHMARK A cut mark in stone/brick. Some have been found upside-down. |
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| RIVET WITH CUT BENCHMARK. A rivet is a small round headed bolt no more than half and inch (12mm) in diameter. They are situated ABOVE a cut benchmark. |
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| FUNDAMENTAL BENCHMARK. These are about a foot high (30 cm) with a large bolt on top, with a metal plaque. Worth noting also is that some standard FBMs have been cut down to ground level. Some of these have a new bolt on top, but not all. |
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FLUSH BRACKET. These can be found on trig pillars, buildings, bridges etc. They all have an individual number, which you should log. |
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| SURFACE BLOCK. A rivet set in a concrete base about 6 inches across (15cm) flush at ground level.
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RIVET AND BENCHMARK (OLD STYLE) I have been told that it is the old style of rivet. It is like a headless nail which has been driven into the granite. The top of the stump protrudes out of the rock by about a quarter of an inch (6mm). The only place I have found one is on Dartmoor, where there are several. |
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| PIVOT BENCH MARKS. A benchmark which has an empty hole above it. There is no horizontal mark. |
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| PROJECTING BRACKET. These brackets are the predecessor to the Flush Bracket. 258 listed on OSBM. |
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| BERNTSEN. Visible is a metal circular lid about 6 inches across (15cm) at ground level, covering a brass bolt. |
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| CURRY STOOL is a horizontal concrete tripod at ground level with arms about 3 feet (1m) long & a centre stud. 9 known in the UK. |
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BLOCKS. These are similar to a surface block, often replacing (and made from the remains of) a destroyed trig pillar. 17 known in the UK.
WM8CME is one |
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| ACTIVE STATIONS contain a GPS receiver antenna and sometimes meteorological instruments. Active Station Map. (Not publicly listed by OS.) Find an Active Station.
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| CONCRETE RING with a centre stud. 2 feet (55cm) diameter. 6 known in the UK. |
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| (The pictures below have been borrowed from T:UK which will be replaced with our own waymarking photos when the objects have been submitted. If you are submitting any of the objects please could you let a manager know.) |
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| FENOMARK. 10 of these are known in the UK. |
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| CENTRE is a small cross engraved in metal. There are 2 known in the UK. |
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| GRAVITY FBM. Similar to a standard FBM, but bigger, and with a flush bracket. 4 known in the UK. |
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| BURIED BLOCKS 5 known. Like Surface Blocks but roughly one to two feet underground. |
(No photos in Waymark database yet.) |
| SPIDER. There are 6 left in the UK. They are similar to the spider on top of standard trig pillar, but placed elsewhere. e.g. in a wall |
(No photos in Waymark database yet.) |
| There are ANOMILIES. A raised block without Flush Bracket but with OSBM bolt under a trap door. |
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| Other survey marks. |
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| ADMIRALTY
HYDROGRAPHIC DEPARTMENT LEVEL MARKER. These markers are flat and about 6 inches across (15cm) , set in rock. |
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EABM (Environment Agency Bench Mark) |  |