ch 39 tides and sea walls
TRANSCRIPT
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From Corn to Cordite. Copyright John Williams 2010
Chapter Thirty Nine :
Tides and Sea walls.
Contents:
The Suggestion is That Tidal heights were greater in past times.
The evidene suggests that a hange in tidal heights has happened.
The arguments: !rom authorities and e"perts on greater tidal heights in the past
are as #ollows.
The $uth %rewery: %ier&rouweri'en (ran'e&oom )erenigde.
* tide ta&le #rom 1+,0.
-e#erenes.
The Sea walls at itsea
The /arly Sea walls proteting itsea all /state and the Sluie.
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From Corn to Cordite. Copyright John Williams 2010
Chapter Thirty Nine :
Tides and Sea walls.
t would &e interesting to disover what would the height o# the tides &een inpast times is there any evidene o# hange.
The Suggestion is That Tidal heights were greater in past times:
Should the reader want a short onise e"planation o# sea levels then this
is the re#erene #or you: ordon. $.3 4ean Sea 3evel around the %ritish sles.
5*6
$alton and 3aver 5%6 suggested that an e"amination o# tidal height in
Colhester showed that ranaries whih were not 700 years old were regularly
#looded in 1800. The #oundation level o# the -oman settlement in the area was at
the &ottom edge o# low water spring tides. * 9ui alulation shows that allthings &eing e9ual then this would &e e9uivalent to 1+ #eet &elow the ranaries.
The evidene suggests that a hange in tidal heights has happened:
This evidene &y $alton and 3aver suggests that sea level rises were
happening in the 1+thentury. 5%6 Jensen states that Sea levels in -oman times
were 1; #eet lower that today. 5C6.
Why would the sea level &e rising sine -oman times< We have to
onsider phenomena nown as =/ustay> and =sostay>. /ustay is the inreased
amount o# water held in the oeans &asins? i# it inreases then #looding is
possi&le in plaes. sostay is di##erent? this is when the rust or the land &ends?
tilts or de#orms. The e##et o# this &ending or tilting is seen in the Thames valley.
The theory goes lie this? during the last ie age huge masses o# ie rested on the
northern parts o# /ngland and Sotland this depressed the level o# the land and
tilted the oast in the south upwards. When the ie melted the weight was
removed and the land mass started to reover and rise so Sotland rose &ut the
Thames valley san. /videne e"ists to show that the Sottish &eahes have risen
2; #eet and lowering has ourred in the Thames area.586
The arguments: !rom authorities and e"perts on greater tidal heights in the past
are as #ollows:
Taser omments that a great deal o# em&aning was done &y the
-omans who were master &uilders? this is easily evidened at %aring and
$agenham. /lsewhere it was the $uth who were involved in em&aning the
Thames. 5$6
!air&ridge loos at hanges during the -oman period? the lower plot on
the sea level graph 5shown on age @116 shows that in %CA*$ the level drops
until *$ 1;0 then rises until *$ ;00 the drops again. 5/6? 5!6? 56? 56? 56? 5J6.
t would not &e unreasona&le to e"amine the #ortunes o# a loal port that
had &een ative sine the1;th and 1Bth
Century. The Town o# 3eigh would suitadmira&ly.
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From Corn to Cordite. Copyright John Williams 2010
3eigh was desri&ed in 1;B; as: A very proper towne, well furnished of
(Rubbed) mariners, where ships do ride, all maner cranes and other thinges.
Fourteen ships, 6!"# tons $ mariners% 516 and in 1B07 it is reorded that 8
vessels o# 200@00 Tons were &ased in 3eigh.526. The 3eigh &ased 7;0 ton ship
the =lo&e> was plying her trade to the /ast ndies while the vessel =3ittle John>
was visiting South *#ria.n 1;,+? 3eigh sent eight ships and two innaes 5small support vessels6 to
support $raes !leet against the Spanish. Then in 1;,8 3eigh sent ships to
ortugal to support $rae as =ired 4erhantmen> #or whih they reeived
2 shillings per ton per month. 576.
n 1B18 3eigh had 21 vessels. arwih and Colhester having 7B and 20
respetively. )ange? %en#leet and !o&&ing having only one. 5@6.
n 1B2, it is reorded that the County only had 708 sailors and 7;+
!ishermen? with 7@ ships at 100 tons and 1B ships at 8; tons.
We must ompare this with #igures #or 1;+2 when 3eigh alone had 71
vessels with 270 mariners and #ishermen. 5;6.
*n interesting #at is that there was a small port alled 4ilton o# 4iltonamlet? it was reorded that in the early 1B00>s it had si" vessels &etween 120
and 700 tons and served the /ast ndies. t no longer e"ists? Nihols reords that
4orant in 1+B, states that the remains o# a hapel an &e seen at the low water
mar. The loation seems to &e somewhere on the Southend Sea#ront. 5226.
Something was happening? orts lie 3eigh would &e very susepti&le to
what is alled &y Sea#arers =Constrained &y $raught>? this simply means that
there needs to &e enough water to allow the ship to enter the do or ome
alongside to &e unloaded? larger ships would go elsewhere. t is not impossi&le
and worth onsidering? that the 4ediaeval su&mergene had some in#luene on
this onstraint.
t is important to point out that #rom 1+;01,@0 huge amounts o# orn
went to $uth &reweries the repeal o# orn laws in the early 1,00>s aused it go
the other way when the importation o# orn inreased? possi&ly on #oreign ships.
5B6? 5+6? 586? 5106.
%ier&rouweri'en (ran'e&oom )erenigde.
* )ery old $uth &rewery esta&lished in 1B+1? now losed. To 9uote #rom
the $uth Tourist %oard. ollandDs hop gardens #irst appeared in the 1@th
entury and &reweries &lossomed during the 4iddle *ges? although the
housewives did not stop &rewing their own &eer. /very $uth ity had a
&rewery? and aarlem? $el#t? ouda? and *mers#oort produed enough &eer #or
e"port to !landers. *msterdam &eame the ma'or &rewing enter in the 1;th
entury. %y the 1+th entury there were +00 &reweries in olland and aninrease in demand #or &eer as it was used #or &oth drining and ooing
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raph o# Tidal variation over time. 5,6
/videne and arguments to e"plain how silting has ourred altering the usage o#
any tidal draught:
t an &e argued that the slight lowering o# the availa&le draught and the
ontinuing pro&lems aused &y 3ondon %ridge impeding o# the Thames #low andwas ausing siltation. Today? 3eigh is somewhat silted up and would have
di##iulty in handling the num&er and siEe o# vessels as #ormerly even i# the
inreased tidal height is allowed #or.
t is lear that an e"amination o# the Thames tidal region is that
enormous 9uantities o# silt streth #or miles. What aounts #or this apparent
hange