castle castle artillery fort located west bank kent village opposite short distance time key naval facility fort intended protect dockyard ships royal_navy anchored constructed orders elizabeth period tension spain european powers castle consists main building protected curtain wall towers triangular gun platform projecting river garrisoned men peak armament cannon despite strategic importance castle defences thames badly neglected 17th century mounted unexpected naval raid june dutch fleet able breach defences capturing warships burning anchor river chatham worst defeats suffered royal_navy castle acquitted better defensive sites upper despite lack gun fire fort adjoining forced dutch retreat couple days able burn dockyard raid exposed weaknesses defences led castle losing role artillery fortification new stronger forts built following centuries culminating construction massive forts castle naval ammunition depot storing great quantities gunpowder ammunition cannon warships came chatham repair resupply remained military use late castle subsequently opened public english_heritage property history strategic context river major tributary thames merging estuary miles east london upper reaches rochester confluence thames sand mud banks miles water flows slowly strong currents free rocks surrounding hills provide shelter south west wind characteristics section river rochester bridge desirable anchorage large ships anchored safely grounded repairs complexity channel navigation provided defensive advantages henry_viii reign upper gradually principal anchorage ships royal_navy ordinary commission usually stripped sails rigging state opportunity taken refit repair facilities built towns chatham eventually nucleus chatham dockyard time elizabeth came throne royal fleet section known chatham anchorage thames defended naval attack henry_viii time built chain coastal defences medieval castles castle existed river south bank intended defend approaches little use defence pressing need proper defences protect vulnerable ships shore facilities upper construction castle commissioned order indifferent persons chose site opposite creek chatham acres land belonging thomas acquired crown possibly purchased sum military engineer sir given task designing new fortification appears fully occupied working defences project carried designs deputy took role surveyor chief carpenter rochester mayor navy managed project day day basis handled accounting castle original appearance differed significantly today arrow shaped facing main block original design towers end water frontage subsequently replaced towers different design gatehouse moat later additions number derelict buildings rochester castle pulled provide stone castle main structure completed took years extra funds finish project total cost came improvements repairs late 16th century tensions grew protestant england catholic spain leading ultimately anglo spanish war spain strong position attack south england possessions new fortifications erected including chain stretched width river castle castle poorly manned lord high admiral 1st earl nottingham highlighted recommended garrison increased garrisoned eighty men paid day equivalent today continued fears spanish led castle defences strengthened sir shaped timber erected water block attempted landings ditch metres deep metres wide dug castle flanking turrets constructed protect site present north south towers raised high added edge gatehouse built protect castle survey conducted recorded castle guns plus guns split known bay castle armament consisted cannon chambers armed eighteen guns recorded mounted castle years later garrison armament included indication military value late date time castle state disrepair raising mechanism broken gun platforms needed repairs courtyard wall collapsed new curtain wall built protect castle foundations reported washed away tide appears allowed fall ruin castle fell parliamentary hands fight english civil war broke subsequently intern royalist officers royalist uprising took place kent essex seizing number towns including rochester dover defeated june castle restored parliamentary hands parliamentary commander chief sir inspected castle ordered repairs strengthening gun platforms appears height gatehouse increased time north south towers built appear left open course repairs making suitable use troop accommodation raid castle saw action history dutch raid june second anglo dutch war dutch nominal command lieutenant admiral bombarded captured town sailed thames chatham way past chain supposed block river sailed past castle towed away unity burning ships anchor dutch anchored overnight june duke took charge defences ordered hasty construction gun battery guns taken chatham castle guns garrison muskets new battery bombard dutch ships attempted second time sail past chatham dutch able burn ships anchorage unable progress withdraw outcome raid described worst naval defeat england sustained castle acquitted eyes contemporary observers despite inability prevent raid dedication garrison praised pro government reported warmly entertained major commanded sir battery received shattering ships sinking manned great number men kill prisoners taken forced retire military historian observes presenting facts favourable light ministers secretary got closer truth noted diary castle garrison poorly castle received hurt played long shot till hardly gun left carriages badly provided usage magazine naval facility castle neglected previously dutch attack prompted government order maintained fort place strength end raid marked end castle career fortress new powerful forts built farther aim preventing enemies reaching chatham making castle redundant converted place stores magazines new purpose supplying munitions naval warships anchored guns gun carriages shot gunpowder stored great quantities main building castle increased height floors reinforced accommodate weight england leading magazine iron guns standing carriages ships carriages pieces iron shot muskets types barrels powder considerably held largest magazine tower london castle ceased magazine converted gunpowder explosives stored magazines continued built nearby linked originally narrow gauge line built steam locomotives castle associated depot came control admiralty ending arrangement managed site admiralty providing funding group facilities country castle magazine time testing firearms explosives castle remained military ownership museum 1920s onwards second world war castle service damaged enemy bombs fell bombing pieces plaster castle south tower gatehouse discovered old graffiti including drawing ship dated castle today following end war admiralty gave approval castle opened public subsequently underwent degree restoration castle scheduled ancient monument january currently managed english_heritage remains description castle buildings constructed combination blocks plus red bricks timber main building rectangular block measures aligned north east south west direction west bank later known magazine changed considerably original construction included limited accommodation possibly small second storey placed gun platforms roof building converted magazine changes obscured earlier design second storey appears extended length building covering earlier rooftop gun platforms gave room storage interior ground floor divided compartments floor copper doors reduce risk sparks stores housed floor raise stores circular staircase building gives access castle main gun platform water low triangular structure projecting river castle main armament mounted open air represented mid-19th century guns original carriages facing downstream upstream rounded designed shot water additionally protected wooden follows triangular course metres river present modern recreation original structure pair towers stand river edge short distance main building originally open backed structures gun platforms situated floors providing flanking fire line ditch castle perimeter later adapted use accommodation backs closed bricks towers increased height provide storey traces gun seen point original said use castle governor lack comfort meant successive governors declined live towers linked main building curtain wall additional cannon north south castle principal buildings situated east rectangular courtyard stand large turkey oaks said grown brought war stone curtain wall topped brick surrounds courtyard standing thick high courtyard entered north western gatehouse gun additional defensive strength substantially rebuilt badly damaged fire traces seen form stones floor walls central gateway round arch leads passage gives access courtyard gateway late 18th century clock inserted existing structure wooden added early 19th century modern building curtain wall surrounded dry ditch originally nearly wide deep partially visitors castle crossed longer extant reach gatehouse secondary entrance castle provided port north wall inside curtain wall brick foundations buildings seen originally lean structures constructed 17th century provide storage facilities garrison short distance south west castle barracks block associated storage buildings constructed soon built replace original accommodation castle redeveloped convert magazine changed little externally years rare surviving example 18th century building type distinct barracks built england depot buildings associated castle survive area immediately north east remain hands constructed earlier gun traces seen form broad bank running north east castle depot
Upnor Castle