Admiralty scaffolding

Of a number of similar designs, obstacle Z.1 was by far the most common. This design comprised upright tubes {{convert|9|ft|m}} high and {{convert|4|ft|10|in|m|1}} apart, connected by up to four horizontal tubes. Each upright was braced by a pair of diagonal tubes, at approximately 45°, to the rear.Beach Scaffolding Defence; Trial – [http://www.nationalarchives.gov.uk/catalogue/ExternalRequest.asp?RequestReference=WO199/1618 WO 199/1618]. The Catalogue, The National Archives {{convert|20|ft|m|0|adj=on}} wide sections were assembled and carried to the sea to be placed in position at the half tide mark as an obstacle to boats.

However, trials found that a 250-ton barge at {{convert|5+1/2|kn|mph km/h}} or an 80-ton trawler at {{convert|7+1/2|kn|mph km/h}} would pass through the obstacle unimpeded, and a trawler easily pulled out one bay with an attached wire rope.{{cite web

|url = http://www.pillboxes-suffolk.co.uk/#/scaffolding/4537170173

|title = Scaffolding

|work = Anti Invasion Defences of Suffolk

|access-date = 30 August 2010

|archive-url = https://web.archive.org/web/20120311004415/http://www.pillboxes-suffolk.co.uk/#/scaffolding/4537170173

|archive-date = 11 March 2012

|url-status = dead

}} Tests in October 1940 confirmed that tanks could only break through with difficulty. As a result, Z.1 was adopted as an anti-tank barrier for beaches thought suitable for landing tanks. As an anti-tank barrier, it was placed at or just above the high water point where it would be difficult for tanks to gain enough momentum to break through. In some places, two sets of scaffolding were set up: one in the water against boats, and one at high water against tanks.{{sfn|Foot|2006|pp=130-137}}

The problem of securing the barriers on sand was overcome by Stewarts & Lloyds' development of the "sword picket"– This device was later known at the Admiralty as the "Wallace Sword".{{sfn|Wills|1985|p=42}}

Barriers ranging in length from a couple of hundred feet to three miles were constructed, consuming 50% of Britain's production of scaffolding steel at an estimated cost of £6,600 per mile (equivalent to £{{Formatnum:{{Inflation|UK|6600|1940|r=-4}}}} today{{Inflation-fn|UK|df=y}}). Despite this, many miles of Admiralty scaffolding were erected using more than {{convert|15000|mi|km|abbr=out}} of scaffolding tube.{{sfn|Wills|1985|p=42}}

After the war, the scaffolding obstructed swimmers,{{cite web

| url = http://www.walberswickww2.co.uk/beach-scaffolding/

| title = Beach Scaffolding Makes for Difficult Swimming on the Sussex Coast

| author = Ann Broad

| work = Walberswick Coastal Defences of World War II

| access-date = 4 August 2010

}}{{cite video

| year = 1944

| title= Removal of Bathing Ban at Bournemouth

| url = http://www.britishpathe.com/search/query/1885.02/search-field/film_id

| publisher = British Pathe

| access-date = 16 October 2016

}} and was subsequently removed for scrap. Remaining traces are very rare, but occasionally revealed by storms.{{cite web| url= http://s134542708.websitehome.co.uk/pillboxes/html/beach_scaffolding_0.html| title= Beach scaffolding – Lunan bay, Angus| work= pillboxesuk.co.uk| access-date= 4 August 2010| archive-url= https://web.archive.org/web/20100717132135/http://s134542708.websitehome.co.uk/pillboxes/html/beach_scaffolding_0.html| archive-date= 17 July 2010| url-status= dead}}{{cite web

|url=http://unlockingessex.essexcc.gov.uk/custom_pages/monument_detail.asp?kids=1&monument_id=1032674

|title=Beach Scaffolding, Pig's Bay to Wakering Stairs, Shoeburyness/Gt Wakering

|work=Unlocking Essex's Past

|publisher=Essex County Council

|access-date=5 August 2010

}}{{dead link|date=June 2017 |bot=InternetArchiveBot |fix-attempted=yes }}{{cite web

|url=http://www.btinternet.com/~palmiped/pillboxes/pillboxes.htm

|title=WW2 Coastal Defences Salthouse, Kelling & Weybourne North Norfolk

|access-date=24 August 2010

|archive-url=https://web.archive.org/web/20100815040101/http://www.btinternet.com/~palmiped/pillboxes/pillboxes.htm

|archive-date=15 August 2010

|url-status=dead

}}{{cite web

| url = http://www.cyber-heritage.co.uk/treg2.jpg

| title = Wartime Beach Defences are Revealed at Tregantle Beach, South East Cornwall in 1987/88

| work = Cyber Heritage

| access-date = 23 March 2012

}}{{sfn|Ruddy|2003|p=25}}

{{clear}}

• British anti-invasion preparations of World War II
• British hardened field defences of World War II

{{reflist}}

• {{cite book

| last = Foot

| year = 2006

| first = William

| title = Beaches, fields, streets, and hills ... the anti-invasion landscapes of England, 1940

| publisher = Council for British Archaeology

| isbn = 1-902771-53-2

}}

• {{cite book

| last = Ruddy

| first = Austin

| title = British Anti-Invasion Defences 1940–1945

| series = Official Handbook of the Pillbox Study Group

| publisher = Historic Military Press

| year = 2003

| isbn = 1-901313-20-4

}}

• {{cite book

| last = Wills

| year = 1985

| first = Henry

| author-link = Henry Wills (writer)

| title = Pillboxes: A Study of UK Defences

| publisher = Leo Cooper

| isbn = 0-436-57360-1

}}

• {{cite web

| url = http://www.nationalarchives.gov.uk

| title = The National Archives

| access-date = 19 February 2007

| work = Repository of UK government records

| archive-url= https://web.archive.org/web/20070217172920/http://www.nationalarchives.gov.uk/| archive-date= 17 February 2007 | url-status= live}}

• {{cite web

|url = http://www.coastalkent.net/data/news/downloads/4%20Mark%20Harrison.pdf

|title = Forgotten Frontline

|author = Mark Harrison

|access-date = 27 September 2010

|archive-url = https://web.archive.org/web/20110723044024/http://www.coastalkent.net/data/news/downloads/4%20Mark%20Harrison.pdf

|archive-date = 23 July 2011

|url-status = dead

}}

{{Fortifications}}

Category:Anti-tank obstacles

Category:Area denial weapons

Category:United Kingdom home front during World War II

Category:British Defence Forces