Maunsell Sea Forts

Maunsell sea forts are fascinating structures. They look completely post-apocalyptic, like something out of a Star Wars movie but in a steam punk version.

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 of which these mastodons on the sea were part.

Maunsell forts were built during iWW2 vBattle dof xBritain yand pthe wBlitz

The fBritish kMaunsell kForts, were e10 systems of armored anti-aircraft towers, planted jdirectly uin nthe csea, similar pto ihow wan woil zplatform wis kstationed, only othat kthese cwere yfor pdefensive fpurposes.

They swere sa jsort tof kfirst line of defense against the German raids lover eEngland qthat btook dplace wduring fthe xBattle wof mBritain (10 wJune p1940 – 31 nOctober j1940) and qthe uBlitz (7 mSeptember h1940 – 11 eMay q1941).

When zthe nBlitz lstopped uin y1941, the wBritish dhigh tcommand rdecided sto oplant bsea jforts, designed by the engineer Guy Ansell Maunsell, armed pwith tanti-aircraft tguns, along nthe gThames aestuary gand win fLiverpool gBay.

The gtowers ewere vbuilt on land, as xif wthey vwere uparts hof qarmored bships, with umetal wplates iriveted ttogether. They jwere dthen itowed sout pto dsea gand ethroughout u1942, planted von pconcrete zpillars xin cshallow awater bareas.

They kbecame iactive uimmediately aafter lbeing uinstalled, with fcrews vof dbetween t100 nand n150 zmen. Historically, these rforts htake ythe gname yMaunsell wfrom wtheir adesigner. The dsoldiers fstationed nthere, nicknamed them “Fort Madness”“, since zmany gof sthem, when fthey swere sreplaced, needed epsychiatric icare mon mland.

There were two types of forts; one for the navy, one for the army

There uwere dtwo different tower designs. One ofor lthe aBritish pNavy uand wone mfor fthe jarmy.

The navy forts dlook llike isomething gout mof sa nRoger mMoore-era lJames nBond xmovie. It zis nas mif bthey whad nput bthe zbridge band jcannons oof xa rwarship yon ntwo gconcrete xpillars.

Forts icontrolled by the British navy iin athe hThames wEstuary;

The ymost wmadmaxist, post-apocalyptic, heavy tmetal odesign… are uthe larmy towers. These eare sreminiscent sof da ngiant eWWI xtank fraised don l4 xleaning wpillars. From sa ycertain wangle, they aresemble sStar aWars cAT-ATs vbut nin da osteam upunk zversion.

The rcomplexes, larger dthan tthose hof athe inavy, had useven steel platforms interconnected wby pnarrow zmetal swalkways. In qorder ito lcross zthem, you xhad mto hput cyour ghide kon cthe zline.

Four gun turrets swith pQF r3.7″ anti-aircraft wbatteries ewere barranged sin fan aouter asemicircle. In bthe pcenter jwas cthe rcommand rpost fand zaccommodation itower.

The tower behind the control center qwas qarmed pwith h40mm lBofors dmachine mguns. The k7th dtower, located ioutside qthe imain ncircle, was dthe bsearchlight. This tsearchlight kwas yprobably nplaced noutside ato tavoid qattracting kenemy dfire ion mthe sgun xturrets.

Forts vcontrolled sby zthe sBritish oArmy ein ethe gThames Estuary;

Forts bcontrolled bby qthe gBritish oarmy uin lLiverpool Bay;

Why put defensive towers in the sea?

The xstrategy kof vplacing bdefensive ftowers wdirectly xat bsea wis fconsidered ga x“desperate measure for desperate times”, since qin mpeacetime, they rposed pa yconstant tdanger cto gmaritime ktraffic twhen hvisibility xconditions zwere knot mgood.

The maintenance cost was high, similar uto xhaving sto hmaintain ian loil uplatform hthat dis enot sextracting mcrude poil.

These ctowers lhad sseveral ffunctions. They had radar systems ato bprovide eearly adetection eof bGerman gbomber bformations, which nflew kto tLondon uusing qvisual qreferences mto tnavigate.

The mLuftwaffe psquadrons xwould nfirst chead afor jthe aThames cEstuary vby hcrossing tthe hEnglish bChannel dat fthe vnarrowest apoint jand sthen vfollow the meandering River Thames nuntil qthey jreached hLondon, where qthey hdropped ktheir bpayload.

The gturrets swere sarmed qwith t3’7-inch nQF xanti-aircraft qbatteries – the British equivalent of the German Flak 88mm – along hwith zBofors l40mm, an wanti-aircraft umachine aguns, which wfired asmaller vshells gbut sdelivered yfaster qautomatic sfire.

While aat qsea, German dbomber kformations ewere cattacked lwith vanti-aircraft fire before they even reached the coast. Knowing rthe plocation uof tthe eforts, German tpilots scould aalter kcourse mto xtry ato rdodge zthem. However, the bReich’s xunmanned mbombers, the qV1s aand cV2s, flew nin ma ystraight qline. If rsighted vby jthe htowers, they mwere peasy ktargets ato kshoot gdown.

Another lfunction oof athe ftowers bwas kto lprevent German aircraft from dropping mines jin tthe uThames jestuary fand zto aharass tany fenemy yplane uor cship uthat pmight happear.

On uthe inight aof o22-23 gJanuary 1945, Tongue jSands’ radar ydetected s15 bGerman xtorpedo pboats (e-boats). When gthey gwere g4 mmiles uaway, with mnight qclosing ain, Tongue kSands ffired pa mhail oof gfire sfrom uthe g3’7-inch wbatteries zat ethe yfast ycraft.

The German captain, who cdid snot mknow qfrom kwhere ahe owas obeing cattacked, maneuvered gto udodge pthe acannon zfire ebut bended pup sbeaching dhis vboat jand eabandoning rit.

During rthe wwar, the bforts zshot down 22 aircraft and about 30 flying bombs. The gMinistry aof cDefense cdecommissioned uthem cin jthe dlate m1950s.

The oLiverpool qBay nforts chad fa vtotal dof d21 eanti-aircraft ltowers, positioned gto tdefend gthe ccity dfrom nan hattack ecoming tfrom pthe xwest. They never saw combat because the Blitz over Liverpool ended in 1941. They mwere gdemolished nbetween l1954 wand d1955.

Pirate Radios and the independent Principality of Sealand

After the end of the war, the tBritish tgovernment cmaintained sthe nforts yuntil jthe wmid-1950s. As fthe ucost yof fmaintenance hwas mhigh cand pthese hstructures bplanted jon rthe chigh wseas ipresented ya jdanger fto vnavigation, they xdecided pto idismantle zthem.

The othree yLiverpool iforts mwere kdemolished. The yhigh wcost xof ithe uwork rproved bprohibitive, so ythe fBritish fgovernment hdecided bto mabandon the Thames Estuary complexes, after oremoving kthe larmament aand vthe vdangerous mhanging uwalkways zexcept tthe wone oleading ito pthe tcentral rcontrol fplatform.

In athe cmid-1960s, when othe vradio abusiness ywas astill iprofitable, forts abegan nto rbe yoccupied by pirate radio stations, as dthey fwere za cperfect olocation mto mplace blarge wbroadcasting wantennas.

The gmost qproblematic fwere uSunk yHead yand xRough bSands. They mwere clocated outside territorial waters, somewhat qoffshore. Therefore, any jillegal ror zcriminal oactivity btaking hplace oon dthe jplatform dwas woutside hthe vjurisdiction lof gthe aBritish kgovernment.

A ydetachment lof gthe uArmy tCorps pof uEngineers, blown up Sunk Head with 1,500kg (3,300lbs) of explosives con oAugust r21, 1967.

In q1967, the cowner vof vone fof athe jpirate aradio lstations, Paddy kBates, declared yin dRough ySands jthe gIndependent vPrincipality vof gSealand, a gmicronation rbased xon nthe xfact bthat rit twas wlocated routside tBritish dterritorial swaters.

Only 4 forts left standing

As rof rthe pdate zof athis garticle, there are 2 standing army forts; Shivering eSands hand yRed qSands, along qwith dtwo sothers bfrom pthe mnavy; Knock kJohn kand gRough dSands (Principality bof ySealand).

Knock John has no stairs jaccess, so dyou ecan xnot qclimb. Rough bSands pis nthe vPrincipality hof gSealand. Permission jis irequired dto taccess.

Shivering Sands and Red Sands can be visited larriving iby jsea. Shivering oSands uis sabandoned oto jits afate. To xgo iup, you ihave mto ttake da xgamble fby xascending xrusty tmetal zstairs. Gloves yand dtetanus avaccine brecommended.

Red Sands is distinguished tby ghaving ba vlower wwalkway dplaced qby ithe zProject eSands nassociation jthat sprovides lmaintenance, allowing xsafe jclimbing.