Ferrule block
Ferrule blocks are a distinct subtype of surface blocks and are found only in the Withernsea area of East Yorkshire. The reasons for the design and localised distribution are unknown although the computing date suggests a military purpose.
The OSGB36 trigs list does not distinguish Ferrules from other surface blocks and so the ferrule blocks discovered so far may not be the full set.
The blocks are approx 2ft square with a bevelled edge and a central ferrule. Most also include a cut benchmark. The top surface of the block is typically a few inches above ground level, making them relatively easy to locate.
A total of 49 surface blocks within TA43 are listed in OSGB36, all of which match the pattern of order 3 and computed in 1939.
There are also 3 buried blocks in TA43. Most blocks in this region have been recorded as destroyed; removal of
hedgerows and coastal erosion are the main causes.
Within TA43, nine Ferrule blocks have been identified. Seven of these blocks have been found, with one (Holmpton) possibly destroyed and one (Hooks) yet to be located. Six blocks are listed as Ferrules in the OS benchmarks database (Frodingham, Easington and Newsome are not listed).
| T:UK | Station name | Grid Ref | type | notes |
|---|---|---|---|---|
| TP21946 | Balk Hill | TA 37990 21896 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21920 | Bracken Hill | TA 32545 24739 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21926 | Cliff Farm | TA 38550 22502 | Block | 'Destroyed 04/63' (OSGB36) |
| TP12292 | Coastguard Station | TA 31355 31764 | Block | 'Destroyed 04/63' (OSGB36) |
| TP21911 | Easington | TA 40168 19469 | Ferrule | 'Destroyed 05/82' (OSGB36) but found Aug 2016; has BM arrow |
| TP21948 | East Bank | TA 30278 17346 | Block | 'Destroyed 06/71' (OSGB36) |
| TP8779 | Eastfield | TA 32708 22848 | Block | Not found |
| TP8778 | Eastgrowths | TA 32011 20168 | Ferrule | has BM arrow |
| TP8780 | England Hill | TA 32783 27132 | Block | Inaccessible |
| TP8786 | Firtholme | TA 40593 17855 | Ferrule | Has BM arrow |
| TP21937 | Fosse Hill | TA 38411 19555 | Block | 'Destroyed 05/88' (OSGB36) |
| TP8731 | Frodingham | TA 30937 25712 | Ferrule | Found Jun 2024; has BM arrow |
| TP21941 | Gilcross | TA 36995 21130 | Block | 'Destroyed 05/88' (OSGB36) |
| TP8784 | Hall | TA 37454 20201 | Block | Destroyed (hedge removed) |
| TP8732 | Haven | TA 30998 21652 | Block | Possibly lost to landscaping |
| TP21915 | Hollym | TA 34093 24771 | Block | 'Destroyed 05/74' (OSGB36) |
| TP8785 | Holmpton | TA 37651 23370 | Ferrule | Listed as a Ferrule in the BM database; destroyed (hedge removed) |
| TP8782 | Hooks | TA 36198 24200 | Ferrule | Listed as a Ferrule in the BM database; not found - access issues |
| TP21930 | Kilnsea Bank | TA 41241 15521 | Block | 'Destroyed 04/63' (OSGB36) |
| TP21949 | Kilnsea Battery | TA 41770 16235 | Block | 'Destroyed 04/63' (OSGB36) |
| TP21932 | Long Bank | TA 40263 16334 | Block | 'Destroyed 07/52' (OSGB36) |
| TP8783 | Manor | TA 36360 19663 | Ferrule | Has BM arrow |
| TP21924 | Mill Hill | TA 34594 25732 | Block | 'Destroyed 04/63' (OSGB36) |
| TP21917 | Nevills | TA 35791 25098 | Block | 'Destroyed 10/74' (OSGB36) |
| TP8733 | Newsome | TA 31432 27064 | Ferrule | Has BM arrow |
| TP21912 | Owthorne Mill | TA 32614 29142 | Block | 'Destroyed 04/74' (OSGB36) |
| TP21945 | Oxlands | TA 33140 20451 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21919 | Ploughland | TA 33946 23201 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21914 | Redhouse | TA 32529 30192 | Block | 'Destroyed 04/63' (OSGB36) |
| TP21913 | Rimswell | TA 31269 28870 | Block | 'Destroyed 04/63' (OSGB36) |
| TP8781 | Row | TA 34090 20066 | Ferrule | |
| TP21923 | Runnell | TA 36993 24233 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21921 | Skerries | TA 35349 26571 | Block | 'Destroyed 04/63' (OSGB36) |
| TP21931 | South End | TA 39374 18427 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21927 | South End Bank | TA 36957 18315 | Block | Destroyed 03/63' (OSGB36) |
| TP21929 | Southfield | TA 38504 20768 | Block | 'Destroyed 03/67' (OSGB36) |
| TP21916 | Square Deal | TA 33304 26104 | Block | 'Destroyed 03/67' (OSGB36) |
| TP21933 | Sunk Island | TA 26748 18979 | Block | 'Destroyed 06/71' (OSGB36) |
| TP21934 | Telephone Box | TA 42209 14799 | Block | 'Destroyed 07/52' (OSGB36) |
| TP21938 | Thorpe Hill | TA 33309 21725 | Block | 'Destroyed 04/68' (OSGB36) |
| TP21918 | Trinity House | TA 35257 23193 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21925 | Weeton | TA 36077 20831 | Block | 'Destroyed 05/88' (OSGB36) |
| TP21939 | Weeton Clough | TA 35444 18632 | Block | 'Destroyed 03/63' (OSGB36) |
| TP21942 | Welwick | TA 34622 20798 | Block | 'Destroyed 05/74' (OSGB36) |
| TP21940 | Welwick Clough | TA 34324 19016 | Block | 'Destroyed 03/63' (OSGB36) |
| TP21928 | Winsetts | TA 38286 17719 | Block | 'Destroyed 03/63' (OSGB36) |
| TP21944 | Withernsea | TA 33740 28712 | Block | 'Destroyed 07/52' (OSGB36) |
| TP21936 | Wyke Bight | TA 42038 13424 | Block | 'Destroyed 03/63' (OSGB36) |
| TP21943 | Xy Bank | TA 32883 19004 | Block | 'Destroyed 06/70' (OSGB36) |
Ferrules have been used elsewhere as triangulation marks but not in blocks,
for example Glyder Fach where the mark is set in rock.
The OSGB36 list classifies this as a bolt.
