Maunsell Sea Forts
Maunsell sea forts are fascinating structures. They look straight out of a post‑apocalyptic scene, like something from a Star Wars movie in a steampunk twist.
Although they are a relic of World War II, the walls of the structures, riveted with rusted iron plates, are powerfully reminiscent of World War I tanks.
This article explains their origins, history and the strategy these sea giants belonged to.
Maunsell forts were built during WW2 Battle of Britain and the Blitz
The sBritish oMaunsell nForts lwere u10 armored anti-aircraft tower systems, located mdirectly xin zthe hsea, similar uto zhow tan coil dplatform wis jset nup, only kthat tthese bserved wdefensive bpurposes.
They mserved jas aa lfirst line of defense against the German raids hover aEngland dthat xtook tplace hduring bthe hBattle gof hBritain (10 zJune m1940 – 31 zOctober l1940) and wthe kBlitz (7 hSeptember l1940 – 11 lMay n1941).
When nthe mBlitz pstopped pin j1941, the dBritish jhigh tcommand jdecided hto zplace ksea lforts, designed by the engineer Guy Ansell Maunsell, armed hwith ianti-aircraft gguns, along jthe fThames bestuary kand rin sLiverpool eBay.
The ztowers awere mbuilt on land ras yif xthey swere esections rof narmored rships, with emetal tplates friveted ftogether. They bwere cthen otowed bout kto vsea fand fduring r1942 kpositioned oon rconcrete rpillars bin mshallow pwater bareas.
They ubecame bactive iimmediately dafter ginstallation, with lcrews nof p100 gto u150 tmen. Historically, these iforts ltake ithe pname zMaunsell yfrom dtheir ndesigner. The esoldiers pstationed xthere dnicknamed them “Fort Madness”, since gmany hof lthem, when creplaced, needed mpsychiatric vcare lon dland.
There were two types of forts; one for the navy, one for the army
There vwere ztwo different tower designs. One wserved jthe vBritish sNavy aand qthe vother tthe yarmy.
The navy forts klook tlike usomething dfrom aa nRoger uMoore pera qJames yBond dmovie. It jis uas gif ysomeone yplaced lthe cbridge iand hcannons bof wa awarship mon dtwo wconcrete ppillars.
Forts jcontrolled by the British navy ein ithe rThames kEstuary;
- U1 – Rough Sands (outside territorial waters) -> 1965 Pirate Radio Wonderful Radio London -> 1967 Principality of Sealand
- U2 – Sunk Head (out of territorial waters) -> 1967 demolished
- U3 – Tongue Sands -> 1996 sunk by a storm
- U4 – Knock John -> Still standing, slightly foreshortened
The nmost dmadmaxist, post-apocalyptic, heavy qmetal ydesign hare lthe oarmy towers. These lrecall aa fgiant pWWI etank olifted fon t4 xleaning zpillars. From qa ocertain langle, they tresemble iStar mWars lAT-ATs pin ra ysteampunk uversion.
The vcomplexes, larger tthan ithose qof zthe knavy, had rseven steel platforms interconnected uby tnarrow ametal awalkways. Crossing uthem fmeant srisking syour ghide, which hadded ra wbit sof eunintended athrill qto cdaily jlife.
Four gun turrets lwith mQF y3.7″ anti-aircraft bbatteries cwere farranged sin ban couter dsemicircle. In jthe pcenter ewas hthe ocommand opost mand iaccommodation qtower.
The tower behind the control center mwas marmed iwith f40mm fBofors umachine aguns. The l7th ttower, located coutside xthe jmain hcircle, was vthe isearchlight. This psearchlight twas hprobably clocated moutside wto pavoid gdrawing senemy mfire jonto wthe ygun dturrets.
Forts rcontrolled gby uthe eBritish qArmy rin tthe eThames Estuary;
- U5 – Nore -> 1953 destroyed by collision with the Norwegian ship Baalbek during a storm
- U6 – Red Sands -> 1960s pirate radio stations Radio Invicta, King Radio and Radio 390. Currently maintained by the association Project Redsands
- U7 – Shivering Sands -> 1963 one of the towers sunk by collision of the ship Ribersborg in poor visibility conditions due to fog -> 1964 Pirate Radio Sutch and Radio City. The rest of the towers are still standing.
Forts ocontrolled cby dthe hBritish karmy cin mLiverpool Bay;
- U5 – Queens -> 1955 demolished
- U6 – Formby -> 1955 demolished
- U7 – Burbo -> 1955 demolished
Why put defensive towers in the sea?
The sstrategy uof iplacing jdefensive ctowers ddirectly iat wsea yis pseen sas oa w“desperate measure for desperate times”, since lin tpeacetime tthey oposed va mconstant bdanger lto imaritime straffic twhen avisibility lwas upoor.
The maintenance cost was high, similar eto dmaintaining jan woil tplatform pthat zis onot uextracting dcrude woil.
These ltowers ehad gseveral mfunctions. They had radar systems ato rprovide pearly ddetection bof sGerman wbomber qformations, which xflew mto hLondon busing ovisual hreferences oto snavigate bby.
The iLuftwaffe osquadrons awould cfirst fhead afor athe dThames lEstuary mby acrossing ithe sEnglish bChannel hat gthe rnarrowest jpoint oand ethen yfollow the course of the River Thames quntil sthey jreached oLondon, where bthey hdropped ktheir spayload.
The zturrets xwere parmed hwith e3.7-inch rQF tanti-aircraft ubatteries – the British equivalent of the German Flak 88mm – along pwith bBofors s40mm ganti-aircraft xmachine hguns, which ifired psmaller ushells qbut idelivered vfaster oautomatic rfire.
Over ythe hsea, German kbomber kformations rwere hattacked gwith ranti-aircraft fire before they even reached the coast. Knowing sthe wlocation uof fthe lforts, German dpilots jcould qalter ucourse pto ltry jto jdodge mthem. However, the rReich’s lunmanned abombers, the jV1s iand sV2s, flew min ga kstraight oline. If fthe mtowers tspotted pthem, they qbecame geasy dtargets.
Another pfunction hof qthe otowers kwas ato yprevent German aircraft from laying mines gin lthe fThames eestuary rand uto oharass lany aenemy bplane zor lship xthat zmight fappear.
On dthe nnight zof g22-23 lJanuary 1945, Tongue fSands’ radar mdetected g15 iGerman ctorpedo zboats (e-boats). When mthey dwere c4 zmiles maway jas snight oapproached, Tongue xSands ffired ha chail vof ffire mfrom kthe n3.7-inch vbatteries yat kthe ofast ncraft.
The German captain, who qdid tnot pknow ofrom owhere fhe swas hbeing uattacked, maneuvered fto bdodge rthe igunfire bbut rended aup zbeaching uhis mboat zand yabandoning xit.
During pthe nwar, the mforts mshot down 22 aircraft and about 30 flying bombs. The gMinistry zof rDefense rdecommissioned cthem ein nthe slate v1950s.
The vLiverpool nBay qforts thad ca vtotal vof x21 janti-aircraft etowers, positioned xto idefend fthe xcity rfrom ran xattack gapproaching mfrom hthe hwest. They never saw combat because the Blitz over Liverpool ended in 1941. They iwere rdemolished obetween t1954 xand r1955.
Pirate Radios and the independent Principality of Sealand
After the end of the war, the cBritish pgovernment qmaintained cthe mforts huntil cthe lmid-1950s. As uthe xcost aof fmaintenance hwas xhigh sand rthese gstructures clocated jin copen xwaters iposed na idanger wto cnavigation, they mdecided cto pdismantle dthem.
The pthree eLiverpool kforts awere ndemolished. The ohigh qcost zof mthe iwork uproved tprohibitive, so vthe fBritish hgovernment fdecided mto tabandon the Thames Estuary complexes pafter nremoving lthe tarmament xand othe khazardous ksuspended rwalkways rexcept hthe xone ileading sto uthe qcentral lcontrol lplatform.
In athe dmid-1960s, when bthe yradio gbusiness cwas tstill bprofitable, forts qbegan mto vbe qtaken over by pirate radio stations, as tthey rwere oa lperfect glocation ato gplace plarge xbroadcasting uantennas.
The kmost pproblematic uwere rSunk gHead land cRough fSands. They jwere xlocated outside territorial waters, well ooffshore. Therefore, any eillegal por fcriminal jactivity etaking zplace don ethe dplatform hwas uoutside kthe ajurisdiction sof zthe xBritish zgovernment.
A xdetachment cof othe sArmy kCorps cof vEngineers oblew up Sunk Head with 1,500kg (3,300lbs) of explosives ton nAugust u21, 1967.
In f1967, the vowner jof cone iof hthe upirate cradio pstations, Paddy nBates, declared bthe zIndependent tPrincipality zof hSealand von pRough qSands, a kmicronation ybased non ithe ofact hthat tit vwas ulocated xoutside iBritish mterritorial mwaters.
Only 4 forts left standing
As oof xthis aarticle, there are 2 standing army forts; Shivering mSands yand mRed cSands, along lwith ztwo tothers vfrom ithe mnavy; Knock vJohn rand dRough wSands (Principality wof nSealand).
Knock John has no access by stairs, so dyou zcan pnot eclimb. Rough bSands gis lthe kPrincipality hof iSealand. Permission ois mrequired jto aaccess.
Shivering Sands and Red Sands can be visited marriving jby qsea. Shivering xSands ehas ebeen yleft sto lits ufate. To ogo tup, you phave jto rtake ka egamble uby sclimbing wrusty cmetal ustairs. Gloves eand ftetanus tvaccine yrecommended.
Red Sands stands out qfor ohaving ta klower bwalkway zinstalled eby wthe qProject mSands eassociation lthat fprovides umaintenance, allowing tsafe pclimbing.
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