Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 21, 2015 13:24:19 GMT
Thanks for the detailed feedback on my work and what you think of me.
|
|
|
|
Post by aliveandkicking on Apr 22, 2015 13:21:38 GMT
I got a reply back from public relations at Trinity house that was most unsatisfactory. Evidently the person who replied was only a media person >>Even at 25NM in clear conditions the light should be visible regardless of observer height. I have therefore written again dealing with the points raised and asking them to reconsider what they are telling me. ------------------------------------------------------ Dear XXXXXXXXXX Thanks for the reply This web page: www.trinityhouse.co.uk/lighthouses/lighthouse_list/st_catherines.htmlSays the light is visible up to 30nm. It also says the range is 25nm. Because of the curvature of the earth a low lying light cannot be seen at a distance of 25NM. The web site you referred me to: www.trinityhouse.co.uk/news_info/education/projecting-the-light.htmlIs probably talking about luminous range rather than geographical range. Could you please check what technical terms are behind the use of range on your web pages please and let me know once more? Yours sincerely xxxxxx |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Apr 22, 2015 13:36:08 GMT
Thanks for the feedback, and the update on your research.
|
|
|
|
Post by aliveandkicking on Apr 27, 2015 22:24:15 GMT
I have got another reply back from trinity house.
---------
Dear XXXXXXXXXXX
Having forwarded your enquiry to our Principal Development Engineer (Visual Signalling), he has asked me to forward the following to you:-
Geographical range = 2.03 x (sqrt Height observer + sqrt Height light)
For a 1m height of observer the geographical range is 15M
For a 30m bridge height the geographical range is 25M
25M range is the nominal range where the visibility is taken to be 10M.
Luminous range does not take into account visibility. Therefore, on a very clear night (visibility of say 20M) the light could have a luminous range of 30M+.
As far as the ‘lume’ goes the lens at St Catherine’s emits a pencil beam, a bit like a torch. Like a torch, the lume can be seen even if the original point that the light came from cannot.
Hopefully this answers your question.
Kind regards,
|
|
