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31./32.  Jahresbericht  des  Deutschen  Hydrographischen  Instituts  1976/77

house,  similar  stations  on  the  lightvessel  "Fehmarnbelt"  and  the  research  platform ­
  "Nordsee"  were  taken  into  operation;  they  transmit  continuous  hydrographic
  data  to  the  DHI  direct.
In  the  measurement  field  off  Sylt,  the  investigations  concerning  the  measurement ­
  of  waves  were  continued.  On  the  basis  of  the  extensive  sea  wave  measurements ­
  made  during  the  JONSWAP*)  Experiment,  a  numerical  method  of
forecasting  sea  waves  was  jointly  developed  with  scientists  of  other  institutes,
and  this  is  being  tested  at  the  present  time.
In  connection  with  the  research  work  and  the  intended  exploration  and  exploitation ­
  on  the  German  continental  shelf,  the  DHI  issued  several  permits  or  extended ­
  existing  permits.
The  scientific  services  of  the  DHI,  which  are  necessary  for  the  safety  of
shipping  (tide  prediction  and  storm  surge  warning  service;  ice  service;  time
and  latitude  service;  geomagnetic  service;  as  well  as  the  testing  of  nautical
instruments)  were  carried  out  as  usual.  As  previously,  Tide  Tables  and  "Gezeitenkalender"
  (tidal  calendar  showing  mainly  times  of  high  and  low  water),
the  Nautical  Almanac,  the  Geomagnetic  Yearbook,  as  well  as  Ice  Reports  and
Ice  Charts,  were  issued.  The  nautical  publication  "Der  Seewart"  and  the  "Deutsche ­
  Hydrographische  Zeitschrift"  were  issued  and  each  comprises  six  numbers
per  year.
In  order  to  obtain  a  deeper  insight  into  the  movement  processes  in  the  course
of  storm  surges  and  to  improve  the  forecasting  of  same,  the  DHI  began  —  in
1976  —  to  adapt  hydrodynamical-numerical  methods  for  the  requirements  of  the
storm  surge  warning  service.  In  1976,  the  time  and  latitude  service  began  the
preliminary  preparations  to  transfer  the  photographic  zenith  telescope  to  the
eastern  outskirts  of  Hamburg,  because  the  increasing  intensity  of  light  at  night
at  its  present  location  severely  hinders  the  observations.
About  30,000  type  tests  resp.  individual  permits,  permissions  to  install,  and
tests  carried  out  on  board  ship,  for  nautical  equipment  and  instruments  were
undertaken.  The  initial  and  repeat  testing  of  position  lanterns  for  vessels  coming
within  the  jurisdiction  of  §  8a  of  the  Seeschiffahrtsstrafien-Ordnung  has  been
replaced  by  an  assurance  of  quality  on  the  part  of  the  manufacturer  and  a
repair  and  maintenance  service  carried  out  by  recognized  repair  firms.  The  DHI
has  compiled  Regulations  for  that  purpose  and  issued  them  on  1  July  1976.  On
the  other  hand,  with  the  coming  into  force  of  the  International  Regulations  for
the  Prevention  of  Collisions  at  Sea  1972,  on  15  July  1977,  the  2nd  Statutory
Amendment  Order  to  the  Ship's  Safety  Regulations,  and  the  revised  text  of  the
German  Collision  Regulations,  the  DHI  was  assigned  further  tasks:  such  as
type-testing  certification,  and  approval  of  the  installation  of  sound  signaland
  manoeuvre  signal  equipment,  as  well  as  the  recognition  of  repair  firms  for
such  installations  and  for  navigation  lanterns.  The  international  co-operation  in
the  field  of  testing  was  continued.
Investigations  and  research  work  were  necessary  in  order  to  test,  amongst  other
things,  the  functioning  efficiency  of  magnetic  compass  installations  on  board

*)  Joint  North  Sea  Wave  Project