DOCSLIB.ORG

Influence of the Spatial Pressure Distribution of Breaking Wave

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Influence of the Spatial Pressure Distribution of Breaking Wave Journal of Marine Science and Engineering Article Influence of the Spatial Pressure Distribution of Breaking Wave Loading on the Dynamic Response of Wolf Rock Lighthouse Darshana T. Dassanayake 1,2,* , Alessandro Antonini 3 , Athanasios Pappas 4, Alison Raby 2 , James Mark William Brownjohn 5 and Dina D’Ayala 4 1 Department of Civil and Environmental Technology, Faculty of Technology, University of Sri Jayewardenepura, Pitipana 10206, Sri Lanka 2 School of Engineering, Computing and Mathematics, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK; [email protected] 3 Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN Delft, The Netherlands; [email protected] 4 Department of Civil, Environmental and Geomatic Engineering, Faculty of Engineering Science, University College London, Gower Street, London WC1E 6BT, UK; [email protected] (A.P.); [email protected] (D.D.) 5 College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK; [email protected] * Correspondence: [email protected] Abstract: The survivability analysis of offshore rock lighthouses requires several assumptions of the pressure distribution due to the breaking wave loading (Raby et al. (2019), Antonini et al. (2019). Due to the peculiar bathymetries and topographies of rock pinnacles, there is no dedicated formula to properly quantify the loads induced by the breaking waves on offshore rock lighthouses. Wienke’s formula (Wienke and Oumeraci (2005) was used in this study to estimate the loads, even though it was not derived for breaking waves on offshore rock lighthouses, but rather for the breaking wave loading on offshore monopiles. However, a thorough sensitivity analysis of the effects of the assumed Citation: Dassanayake, D.T.; Antonini, A.; Pappas, A.; Raby, A.; pressure distribution has never been performed. In this paper, by means of the Wolf Rock lighthouse Brownjohn, J.M.W.; D’Ayala, D. distinct element model, we quantified the influence of the pressure distributions on the dynamic Influence of the Spatial Pressure response of the lighthouse structure. Different pressure distributions were tested, while keeping the Distribution of Breaking Wave initial wave impact area and pressure integrated force unchanged, in order to quantify the effect of Loading on the Dynamic Response of different pressure distribution patterns. The pressure distributions considered in this paper showed Wolf Rock Lighthouse. J. Mar. Sci. subtle differences in the overall dynamic structure responses; however, pressure distribution #3, Eng. 2021, 9, 55. https://doi.org/ based on published experimental data such as Tanimoto et al. (1986) and Zhou et al. (1991) gave 10.3390/jmse9010055 the largest displacements. This scenario has a triangular pressure distribution with a peak at the centroid of the impact area, which then linearly decreases to zero at the top and bottom boundaries Received: 30 November 2020 of the impact area. The azimuthal horizontal distribution was adopted from Wienke and Oumeraci’s Accepted: 26 December 2020 work (2005). The main findings of this study will be of interest not only for the assessment of rock Published: 6 January 2021 lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with Publisher’s Note: MDPI stays neu- steep foreshore slopes) and exposed to harsh breaking wave loading. tral with regard to jurisdictional clai- ms in published maps and institutio- Keywords: breaking wave loading; impact pressure distributions; offshore vertical cylinders; light- nal affiliations. houses; STORMLAMP project Copyright: © 2021 by the authors. Li- 1. Introduction censee MDPI, Basel, Switzerland. This article is an open access article Offshore rock lighthouses constructed during the Victorian era by the British engineers distributed under the terms and con- are constructed from masonry interlocking blocks. These towers mark submerged or low- ditions of the Creative Commons At- lying offshore rock pinnacles, otherwise difficult to observe from a vessel bridge. In addition tribution (CC BY) license (https:// to being indispensable permanent aids for navigation, these structures are of incalculable creativecommons.org/licenses/by/ cultural significance. The majority of these towers are subjected to direct wave impacts 4.0/). during severe storms. The offshore rocks typically consist of steep foreshores and pinnacles J. Mar. Sci. Eng. 2021, 9, 55. https://doi.org/10.3390/jmse9010055 https://www.mdpi.com/journal/jmse J. Mar. Sci. Eng. 2021, 9, 55 2 of 19 that are barely sufficient in area for the tower foundations. This shoal geometry forces the incoming waves to break either in close proximity to the base of the lighthouse or directly onto the tower, causing unwanted dynamic structural responses which threaten the stability of these structures. Historical anecdotes of former lighthouse keepers provide vital evidence of substantial past impact events. On some occasions, the accelerations due to structure responses could reach values equivalent to modest earthquakes (Raby et al. (2019) [1]). The most sensible method to assess the dynamics of multi-block structure responses due to extreme weather events is by means of a validated 3D distinct element model (DEM) (Pappas et al. (2018) [2]). The external force exerted on the surface of the structure is one of the crucial input parameters that governs the accuracy of the model predictions. However, there are no dedicated formulae to accurately quantify the loads induced by breaking waves for such peculiar configurations. Overall breaking wave forces acting on offshore monopiles can be estimated using Wienke’s formula (Wienke and Oumeraci (2005) [3]); however, this formula is sensitive to wave-induced pressure distribution on the surface of the structure. The wave-induced pressure distribution of an offshore monopile and an offshore lighthouse have significant differences, as wave kinematics for a breaking wave on a shoal are much more complex compared to offshore breaking waves in deeper water. Therefore, dynamic responses of lighthouses might be vastly different to those of offshore monopiles. Detailed numerical modelling of rock lighthouses are rare; therefore, the most probable synthetic pressure distributions were tested using the validated Wolf Rock DEM model (Raby et al. (2019) [1]). The main findings are of interest not only for the assessment of the survivability of rock lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with steep foreshore slopes) and exposed to the harsh breaking wave loadings. The Wolf Rock lighthouse is located approximately 13.5 km south-southwest of the most south-westerly tip of mainland UK. It stands 35.33 m from the foundation to the gallery level (70 rock masonry courses), the lowest 11.98 m (20 courses) being solid except for a water tank. The lighthouse consists of characteristic concave elliptic frustum curve with a maximum diameter of 12.2 m at its base (1st course), which gradually decreases to 5.2 m (67th course). The lowest 20 courses are of a stepped design, with this feature considered as an effective effort to reduce wave runup (Raby et al. (2019), Boyle (1998) [1,4]). After the 67th course, the tower widens again to reach 6.4 m diameter at the 70th course with a recurved profile (radius = 1.15 m) intended to divert the up-rushing wave from the gallery. James Walker initiated the designing of Wolf Rock lighthouse in 1860 based on his prior design and construction experiences on similar rock towers such as Bishop Rock and the Smalls lighthouses (Nicholson (2015) [5]). The design (Figure1a) was completed by William Douglass in 1862 (Douglas (1870, 1871) [6,7]). In 1870, the lighthouse construction was completed after a slow and long construction process due to the severe constraints of working on such a small and low-lying rock exposed to Atlantic gales. This engineering masterpiece has withstood the forces of the ocean since then without requiring any major repairs, but with rigorous inspections and maintenance routines conducted by Trinity House. The UK and Irish General Lighthouse Authorities (GLAs), namely The Corporation of Trinity House, the Northern Lighthouse Board and the Irish Lights (responsible for England, Wales, the Channel Islands and Gibraltar; Scotland; and Northern Ireland and the Republic of Ireland, respectively), need to systematically study the conditions of these heritage structures, primarily focusing on the remaining operational life in light of climate change, with the increase in sea level and the possibility of increased storminess (frequency and magnitude). Therefore, the STORMLAMP project, funded by the UK Engineering and Physical Sciences Research Council (EPSRC), selected Wolf Rock lighthouse (Figure1b ) as one of the seven lighthouses investigated under the project (Raby et al. (2019) [1], Antonini et al. (2019) [8]). This study investigated the differences in the dynamic structure responses of offshore rock lighthouses due to different pressure distributions. The impact area was kept constant in this study, and different impact pressure distributions were tested J. Mar. Sci. Eng. 2021, 9, x FOR PEER REVIEW 3 of 20 storminess (frequency and magnitude). Therefore, the STORMLAMP project, funded by the UK Engineering and Physical Sciences Research Council (EPSRC), selected Wolf Rock J. Mar. Sci. Eng. 2021, 9, 55 lighthouse (Figure 1b) as one
Load more

Recommended publications
  • 'British Small Craft': the Cultural Geographies of Mid-Twentieth
    ‘British Small Craft’: the cultural geographies of mid-twentieth century technology and display James Lyon Fenner BA MA Thesis submitted to the University of Nottingham for the degree of Doctor of Philosophy August 2014 Abstract The British Small Craft display, installed in 1963 as part of the Science Museum’s new Sailing Ships Gallery, comprised of a sequence of twenty showcases containing models of British boats—including fishing boats such as luggers, coracles, and cobles— arranged primarily by geographical region. The brainchild of the Keeper William Thomas O’Dea, the nautical themed gallery was complete with an ocean liner deck and bridge mezzanine central display area. It contained marine engines and navigational equipment in addition to the numerous varieties of international historical ship and boat models. Many of the British Small Craft displays included accessory models and landscape settings, with human figures and painted backdrops. The majority of the models were acquired by the museum during the interwar period, with staff actively pursuing model makers and local experts on information, plans and the miniature recreation of numerous regional boat types. Under the curatorship supervision of Geoffrey Swinford Laird Clowes this culminated in the temporary ‘British Fishing Boats’ Exhibition in the summer of 1936. However the earliest models dated back even further with several originating from the Victorian South Kensington Museum collections, appearing in the International Fisheries Exhibition of 1883. 1 With the closure and removal of the Shipping Gallery in late 2012, the aim of this project is to produce a reflective historical and cultural geographical account of these British Small Craft displays held within the Science Museum.
    [Show full text]
  • Life of William Douglass M.Inst.C.E
    LIFE OF WILLIAM DOUGLASS M.INST.C.E. FORMERLY ENGINEER-IN-CHIEF TO THE COMMISSIONERS OF IRISH LIGHTS BY THE AUTHOR OF "THE LIFE OF SIR JAMES NICHOLAS DOUGLASS, F.R.S." PRINTED FOR PRIVATE CIRCULATION 1923 CONTENTS CHAPTER I Birth; ancestry; father enters the service of the Trinity House; history and functions of that body CHAPTER II Early years; engineering apprenticeship; the Bishop Rock lighthouses; the Scilly Isles; James Walker, F.R.S.; Nicholas Douglass; assistant to the latter; dangers of rock lighthouse construction; resident engineer at the erection of the Hanois Rock lighthouse. CHAPTER III James Douglass re-enters the Trinity House service and is appointed resident engineer at the new Smalls lighthouse; the old lighthouse and its builder; a tragic incident thereat; genius and talent. CHAPTER IV James Douglass appointed to erect the Wolf Rock lighthouse; work commenced; death of Mr. Walker; James then becomes chief engineer to the Trinity House; William succeeds him at the Wolf. CHAPTER V Difficulties and dangers encountered in the erection of the Wolf lighthouse; zeal and courage of the resident engineer; reminiscences illustrating those qualities. CHAPTER VI Description of the Wolf lighthouse; professional tributes on its completion; tremor of rock towers life therein described in graphic and cheery verses; marriage. CHAPTER VII Resident engineer at the erection of a lighthouse on the Great Basses Reef; first attempts to construct a lighthouse thereat William Douglass's achievement description of tower; a lighthouse also erected by him on the Little Basses Reef; pre-eminent fitness of the brothers Douglass for such enterprises. CHAPTER VIII Appointed engineer-in-chief to the Commissioners of Irish Lights; three generations of the Douglasses and Stevensons as lighthouse builders; William Tregarthen Douglass; Robert Louis Stevenson.
    [Show full text]
  • The General Lighthouse Fund 2003-2004 HC
    CONTENTS Foreword to the accounts 1 Performance Indicators for the General Lighthouse Authorities 7 Constitutions of the General Lighthouse Authorities and their board members 10 Statement of the responsibilities of the General Lighthouse Authorities’ boards, Secretary of State for Transport and the Accounting Officer 13 Statement of Internal control 14 Certificate of the Comptroller and Auditor General to the Houses of Parliament 16 Income and expenditure account 18 Balance sheet 19 Cash flow statement 20 Notes to the accounts 22 Five year summary 40 Appendix 1 41 Appendix 2 44 iii FOREWORD TO THE ACCOUNTS for the year ended 31 March 2004 The report and accounts of the General Lighthouse Fund (the Fund) are prepared pursuant to Section 211(5) of the Merchant Shipping Act 1995. Accounting for the Fund The Companies Act 1985 does not apply to all public bodies but the principles that underlie the Act’s accounting and disclosure requirements are of general application: their purpose is to give a true and fair view of the state of affairs of the body concerned. The Government therefore has decided that the accounts of public bodies should be prepared in a way that conforms as closely as possible with the Act’s requirements and also complies with Accounting Standards where applicable. The accounts are prepared in accordance with accounts directions issued by the Secretary of State for Transport. The Fund’s accounts consolidate the General Lighthouse Authorities’ (GLAs) accounts and comply as appropriate with this policy. The notes to the Bishop Rock Lighthouse accounts contain further information. Section 211(5) of the Merchant Shipping Act 1995 requires the Secretary of State to lay the Fund’s accounts before Parliament.
    [Show full text]
  • Black's Guide to Devonshire
    $PI|c>y » ^ EXETt R : STOI Lundrvl.^ I y. fCamelford x Ho Town 24j Tfe<n i/ lisbeard-- 9 5 =553 v 'Suuiland,ntjuUffl " < t,,, w;, #j A~ 15 g -- - •$3*^:y&« . Pui l,i<fkl-W>«? uoi- "'"/;< errtland I . V. ',,, {BabburomheBay 109 f ^Torquaylll • 4 TorBa,, x L > \ * Vj I N DEX MAP TO ACCOMPANY BLACKS GriDE T'i c Q V\ kk&et, ii £FC Sote . 77f/? numbers after the names refer to the page in GuidcBook where die- description is to be found.. Hack Edinburgh. BEQUEST OF REV. CANON SCADDING. D. D. TORONTO. 1901. BLACK'S GUIDE TO DEVONSHIRE. Digitized by the Internet Archive in 2010 with funding from University of Toronto http://www.archive.org/details/blacksguidetodevOOedin *&,* BLACK'S GUIDE TO DEVONSHIRE TENTH EDITION miti) fffaps an* Hlustrations ^ . P, EDINBURGH ADAM AND CHARLES BLACK 1879 CLUE INDEX TO THE CHIEF PLACES IN DEVONSHIRE. For General Index see Page 285. Axniinster, 160. Hfracombe, 152. Babbicombe, 109. Kent Hole, 113. Barnstaple, 209. Kingswear, 119. Berry Pomeroy, 269. Lydford, 226. Bideford, 147. Lynmouth, 155. Bridge-water, 277. Lynton, 156. Brixham, 115. Moreton Hampstead, 250. Buckfastleigh, 263. Xewton Abbot, 270. Bude Haven, 223. Okehampton, 203. Budleigh-Salterton, 170. Paignton, 114. Chudleigh, 268. Plymouth, 121. Cock's Tor, 248. Plympton, 143. Dartmoor, 242. Saltash, 142. Dartmouth, 117. Sidmouth, 99. Dart River, 116. Tamar, River, 273. ' Dawlish, 106. Taunton, 277. Devonport, 133. Tavistock, 230. Eddystone Lighthouse, 138. Tavy, 238. Exe, The, 190. Teignmouth, 107. Exeter, 173. Tiverton, 195. Exmoor Forest, 159. Torquay, 111. Exmouth, 101. Totnes, 260. Harewood House, 233. Ugbrooke, 10P.
    [Show full text]
  • THE TRINITY HOUSE LUNDY ARCHIVE: a PAPER in MEMORY of the LIGHTHOUSE KEEPERS of LUNDY by R.W.E
    Rep. Lundy Field SOc. 44 THE TRINITY HOUSE LUNDY ARCHIVE: A PAPER IN MEMORY OF THE LIGHTHOUSE KEEPERS OF LUNDY By R.W.E. Farrah 4, Railway Cottages, Long Marton, Appleby, Cumbria CAI6 6BY INTRODUCTION The approaches to the Bristol Channel along the northern coast of Cornwall and Devon offer very little shelter for the seafarer during severe weather conditions. Lundy, however, situated at the mouth of the Channel central to the busy sea lanes, is one exception and has provided an important refuge on the leeward side of the island throughout the historic period. Before the navigational aids of the lighthouses were built, the island must also have proved hostile to the mariner, especially during hours of darkness and poor visibility. The number of shipwrecks and marine disasters around the island bear testimony to this. The dangers were considerable; although the tidal streams to the west of Lundy are moderate, they are strong around the island. There are several bad races, to the north-east (The White Horses), the north-west (T)1e Hen and Chickens) and to the south-east. There are also overfalls over the north-west bank. Some appreciation of the dangers the island posed can be seen from the statistics issued by a Royal Commission of 1859 who were reporting on a harbour refuge scheme. They noted that: "out of 173 wrecks in the Bristol Channel in 1856-57, 97 received their damage and 44 lives were lost east of Lundy; while 76 vessels were lost or damaged and 58 lives sacrificed west of Lundy, thus showing the island to be nearly in the centre of the dangerous parts" (quoted in Langham A and M, 1984,92).
    [Show full text]
  • £Utufy !Fie{T{Societyn.F:Wsfetter
    £utufy!fie{t{ Society N.f:ws fetter 9{{;32 Spring2002 CONTENTS Page Report of LFS AGM 2/3/2002 Ann Westcott 1 The Chairman's address to members Roger Chapple 2 Editorial AnnWestcott 2 HM Queen's Silver Jubilee visit Myrtle Ternstrom 6 Letters to the Editor & Incunabula Various 8 The Palm Saturday Crossing Our Nautical Correspondent 20 Marisco- A Tale of Lundy Willlam Crossing 23 Listen to the Country SPB Mais 36 A Dreamful of Dragons Charlie Phlllips 43 § � AnnWestcott The Quay Gallery, The Quay, Appledbre. Devon EX39 lQS Printed& Boun d by: Lazarus Press Unit 7 Caddsdown Business Park, Bideford, Devon EX39 3DX § FOR SALE Richard Perry: Lundy, Isle of Pufflns Second edition 1946 Hardback. Cloth cover. Very good condition, with map (but one or two black Ink marks on cover) £8.50 plus £1 p&p. Apply to: Myrtle Ternstrom Whistling Down Eric Delderfleld: North Deuon Story Sandy Lane Road 1952. revised 1962. Ralelgh Press. Exmouth. Cheltenham One chapter on Lundy. Glos Paperback. good condition. GL53 9DE £4.50 plus SOp p&p. LUNDY AGM 2/3/2002 As usual this was a wonderful meeting for us all, before & at the AGM itself & afterwards at the Rougemont. A special point of interest arose out of the committee meeting & the Rougemont gathering (see page 2) In the Chair, Jenny George began the meeting. Last year's AGM minutes were read, confirmed & signed. Mention was made of an article on the Lundy Cabbage in 'British Wildlife' by Roger Key (see page 11 of this newsletter). The meeting's attention was also drawn to photographs on the LFS website taken by the first LFS warden.
    [Show full text]
  • The Story of Our Lighthouses and Lightships
    E-STORy-OF-OUR HTHOUSES'i AMLIGHTSHIPS BY. W DAMS BH THE STORY OF OUR LIGHTHOUSES LIGHTSHIPS Descriptive and Historical W. II. DAVENPORT ADAMS THOMAS NELSON AND SONS London, Edinburgh, and Nnv York I/K Contents. I. LIGHTHOUSES OF ANTIQUITY, ... ... ... ... 9 II. LIGHTHOUSE ADMINISTRATION, ... ... ... ... 31 III. GEOGRAPHICAL DISTRIBUTION OP LIGHTHOUSES, ... ... 39 IV. THE ILLUMINATING APPARATUS OF LIGHTHOUSES, ... ... 46 V. LIGHTHOUSES OF ENGLAND AND SCOTLAND DESCRIBED, ... 73 VI. LIGHTHOUSES OF IRELAND DESCRIBED, ... ... ... 255 VII. SOME FRENCH LIGHTHOUSES, ... ... ... ... 288 VIII. LIGHTHOUSES OF THE UNITED STATES, ... ... ... 309 IX. LIGHTHOUSES IN OUR COLONIES AND DEPENDENCIES, ... 319 X. FLOATING LIGHTS, OR LIGHTSHIPS, ... ... ... 339 XI. LANDMARKS, BEACONS, BUOYS, AND FOG-SIGNALS, ... 355 XII. LIFE IN THE LIGHTHOUSE, ... ... ... 374 LIGHTHOUSES. CHAPTER I. LIGHTHOUSES OF ANTIQUITY. T)OPULARLY, the lighthouse seems to be looked A upon as a modern invention, and if we con- sider it in its present form, completeness, and efficiency, we shall be justified in limiting its history to the last centuries but as soon as men to down two ; began go to the sea in ships, they must also have begun to ex- perience the need of beacons to guide them into secure channels, and warn them from hidden dangers, and the pressure of this need would be stronger in the night even than in the day. So soon as a want is man's invention hastens to it and strongly felt, supply ; we may be sure, therefore, that in the very earliest ages of civilization lights of some kind or other were introduced for the benefit of the mariner. It may very well be that these, at first, would be nothing more than fires kindled on wave-washed promontories, 10 LIGHTHOUSES OF ANTIQUITY.
    [Show full text]
  • The Corporation Trinity House Deptford Strond
    THE CORPORATION T R I N I TY H O U S E DEPTFORD STROND fl 9192111 0 11 3 E G I N ’h S T O I Y 8 N T T S u C I O N S . J p Q , j i , ; f P R I N TE D ( F O R P R ] V A TE D I S TR I B U TI O N ) B Y N R O W W SMIT H E BBS P O ST E R T O E R H IL L . , 5, , M D C I I I I I I I I I TO H I S R O YAL H I GH N ESS T H E U E O F E I N U R GH K . G. K. T. D K D B , , , aste: of fi s fi nr or ti of O rinit 0 11 3 2 w g g a nu g £ , T H E F O L L O W I N A AR E G P GES , BY E R I I O N P M SS , O R E P E U LY I CA M ST S CTF L DED TED , I H T H E L O YAL U Y W T D T , P R F D E E M O O U N E ST , A N D S P E C I AL C O N GR AT U L AT I O N F T H E I R O CO MP LE .
    [Show full text]
  • 08 Feb 2021 Eindrucksvolle Wahrzeichen an Englands Küste
    Eindrucksvolle Wahrzeichen an Englands Küste Leuchttürme faszinieren. Sie sind romantisch schön, symbolisieren Weite und Freiheit, sind Landmarken für Schiffe, geben Orientierung und weisen den Weg. Wer sich aus der aktuellen Situation schon einmal „wegträumen“ möchte, wird an Englands Küste leicht fündig und kann interessante Wanderungen häufig von Turm zu Turm planen. „Weit über 60 Leuchttürme reihen sich, einer Perlenschnur gleich, entlang der reizvollen und abwechslungsreichen Küste, viele von ihnen sind der Öffentlichkeit zugänglich“, sagt Samantha Richardson, Direktorin der National Coastal Tourism Academy, die das Projekt „England’s Coast“ leitet. „Die Türme stehen abseits üblicher Touristenpfade, eignen sich wunderbar als Fotomotive und in einigen kann man sogar übernachten – weit weg vom Alltag und inmitten traumhaft einsamer Küstenlandschaften. Und sobald die Einschränkungen es zulassen, machen sie eine Reise an die Küste zu einem magischen Besuch“, so Richardson. England’s Coast ist ein Zusammenschluss aller acht ​ ​ ​ englischen Küstenregionen, die mit dem Projekt ihre Kultur, sagenreiche Geschichte und malerischen Küstenlandschaften vermarkten. Auf Flamborough Head, einer Halbinsel zwischen den Buchten Filey und Bridlington in ​ ​ der Grafschaft Yorkshire, stehen gleich zwei Leuchttürme. Der unter Denkmalschutz stehende Kreideturm aus dem Jahr 1669 ist einer der ältesten vollständig erhaltenen Leuchttürme Englands. Unweit hiervon wurde 1806 ein zweiter Turm erbaut. An den unter Naturschutz stehenden Klippen nisten rund um die Türme über 200.000 Seevögel, darunter Basstölpel und Papageientaucher. Der älteste Leuchtturm des Landes und einer der ältesten der Welt steht auf dem Gelände von Dover Castle. Der Turm wurde um das Jahr 43 n. Chr. von den Römern erbaut, als Navigationshilfe zur Überquerung des Ärmelkanals. Die gut erhaltene Ruine ist ein schönes Fotomotiv und steht direkt neben der kleinen Kirche St.
    [Show full text]
  • Introduction: Intertidal Zone and Tides
    Introduction: Intertidal zone and tides People have been populating and using the coast and intertidal zone as a resource since prehistoric times. As a consequence, there are many different kinds of archaeological features to explore in the intertidal and coastal zone. Unlike terrestrial sites, the archaeology in the intertidal zone is not made up of layers; features from prehistory and the modern day can be found on the same horizon, adjacent to each other but separated by thousands of years in date. In addition, the anaerobic conditions created in the intertidal zone mean that finds and features which usually don’t survive, frequently do survive, such as Bronze Age sewn-plank boats and wooden trackways. This booklet of information and activity ideas has been created by Megan Clement from the Heritage Lottery Funded Coastal and Intertidal Zone Archaeological Network (www.citizan.org.uk ) to support the 2017 Young Archaeologists’ Club Leaders’ Weekend. It provides inspiration to help you explore the rich archaeology of the coastal and intertidal zone with groups of young people. Intertidal zone The intertidal zone is the part of the foreshore which gets covered by the sea at high tide and is uncovered at low tide. The area which makes up the intertidal zone can vary dramatically in size. The height of the tide varies too. The Severn Estuary for instance has the largest tidal range in the UK (and the second largest in the world) at 14m. The tidal range is the name given to the difference in the height of the water between low tide and high tide.
    [Show full text]
  • Trevithick Society Journal Cumulative Index to 2021 Pete Joseph
    Trevithick Society Journal Cumulative index to 2021 ITHICK EV SO R C T IE E T H Y T K O K W C I E H T T I H V A E S R T RICHARD TREVITHICK 1771-2021 250TH ANNIVERSARY Pete Joseph & Graham Thorne National Explosives Works, near Gwithian. Concrete loadings for acid tanks near the New Nitroglycerine Hill; St Ives and holiday park in the background. Photo: Pete Joseph Index of Articles to 2020 Journals 1-4 orange covers Journal No. 1: 1973 Editorial (J. H. Trounson) 6 Richard Trevithick - his place in engineering history James Hodge, M.A., C.Eng., F.I.Mech.E., A.F.K. Aes. 9 The Bodmin and Wadebridge Railway C. R. Clinker 29 The story of Wheal Guskus in the parish of Saint Hilary Professor D. G. and Mrs Mary Tucker 49 The Redruth to Penzance turnpike roads Miss E. M. Philbrlck 63 The Liskeard and Looe Canal M. J. Messenger 80 Tin stream works at Tuckingmill Paul Stephens and John Stengelhofen 90 Railway Rhymes No. 1: ‘Success to the West Cornwall Railway’ 26 Book Review An Introduction to Cornish Watermills 87 Journal No. 2: 1974 Editorial (J. H. Trounson) 6 A short history of the Camborne School of Mines L. P. S. Piper 9 Richard Trevithick: new light on his earliest years & family origins Professor Charles Thomas, M.A., F.S.A., Hon. M.R.I.A. 45 The West of England Bacon Co.. Redruth H. R. Hodge and Paul Stephens 55 Notes on some early blowing & smelting sites in the Carn Brea-St.
    [Show full text]
  • Seas Safe for Centuries. These Wasn't Until the Early 18Th Century
    Lighthouses have played a vital role wasn’t until the early 18th century in shining a light to keep sailors, that modern lighthouse construction fishermen and all who travel our began in the UK. An increased in seas safe for centuries. These transatlantic trade encouraged the buildings are iconic in their own building of lighthouses, their right, and are often found in some of purpose being to warn trading ships the most remote parts of the UK. against hazards, such as reefs and rocks. There are more than 60 Dating back to the Roman times, lighthouses dotted around the UK. Britain’s early lighthouses were often The charity Trinty House looks after found in religious buildings sat on many of these lighthouses to help hilltops along the coast. However, it maintain the safety of seafarers. Lizard Point Lighthouse in Cornwall is the site. It was granted, but with one the most southerly lighthouse on condition… At the time, the Cornish mainland Britain. It is a dual towered coast was rife with piracy and lighthouse off the Cornish coast and has smuggling, and so it was required that stood there since 1619. the light was extinguished when the enemy approached, for fear that it A local man, Sir John Killigrew, applied would guide the unwanted criminals for the first patent for a lighthouse on home. The first lighthouse was Egypt's Pharos of Alexandria, built in the third century BC. The lighthouse of Alexandria was made from a fire on a platform to signal the port entrance. Meanwhile, the world's oldest existing lighthouse is considered to be Tower of Hercules, a UNESCO World Heritage Site that marks the entrance of Spain's La Coruña harbor.
    [Show full text]