A Snippet

For navigators, marine or aero, is it GMT = Greenwich Meridian Time or UTC = Universal Time Coordinated?

Well, the Greenwich Meridian is still there, despite the change- over to UTC of many years ago, and literally millions of people still using the expression, inaccurately, for the London borough of Greenwich is after all is said on done, an integral part of the UNIVERSE - can't argue with that! So, in with UNIVERSE and out with GREENWICH! Mind you, our eldest son Steven, his wife and daughter, a Director of the London School of Theatre Arts called Rose Bruford College of Theatre and Performance, who lives in Charlton [on the doorstop of Greenwich] disagrees.

So does that mean that GMT and UTC are the same thing to a navigator [or to anybody for that matter] and the answer is yes, but through a bit of technology which I won't bore you with, UJC is technically just a tiny bit more accurate although for most of us that's of no immediate importance, especially when it comes to closing time especially when the landlord still uses GMT as most of landlubbers do.


For the first seventeen years of my naval career the prime meridian was simply called and known as Greenwich from which all other meridians grew to the east and to the west uniformly, and since the earth is round [spherical = 360°] and there are twenty four hours in a day, every fifteen meridians [degrees] travelled east or west, by sea or by air, is one hour ahead or behind i.e., 360 ÷ 24 = 15. Thirty degrees east = 2 hours, forty five degrees = 3 hours and Singapore is seven and a half hours ahead of Zulu time on the meridian Golf Hotel [GH].  Each divided section is given a letter of the alphabet allowing the time zone kept in that area to be easily expressed as “local time”. For example today, in winter in the UK we keep the prime meridian time which is allocated the letter Z = Zulu but we switch to Alfa time in summer one hour ahead of Zulu time which most of western Europe keeps all the year round all except Eire and Portugal which follow the UK pattern. In my life time, the UK time had two dramatic alterations. The first during WW2 [1940 to 1945] was that we shifted to BDST [British Double Summer Time] which put us into Baker time [the pre mid-1950’s phonetic alphabet].  That meant we were two hours ahead of Zebra time in the summer months and worked that way as follows. In Autumn 1940 we did not put our clocks back one hour so for that winter we remained one hour ahead of Zebra time. In Spring we put our clocks forward putting us into Baker time. This continued throughout the war one hour ahead in winter and two in summer. Then under a Labour Government [and now using a new phonetic alphabet], Wilson tried out the BSTE [British Standard Time Experiment] which involved us following Europeans for a three years experiment by being one hour ahead of Zulu time from Autumn 1968 to Autumn 1971 at which point we reverted back to our normal ways, the way we follow today. 


However, all that changed, for in 1970 -YES 1970 - the expression GMT [Greenwich Mean Time] disappeared altogether and in its place came the rather unusual and seemingly back to front expression of UTC [Universal Time Coordinated] which put timing on a named universal basis [as opposed to a national named basis], although nothing actually changed of significance; nor did the expression GMT disappear, and even today, many still refer to it as such. The time system was now very slightly more accurate than previously because an atomic clock was now the reference point which was transmitted by all the world’s radio stations, ours of course coming from Rugby BT Radio Station. For accurate astro-navigation [for longitude reckoning] time checks were crucial and it was the sole job of the navigating officers yeoman in the surface fleet to record the time error of the ships chronometer [not to alter its recorded time to match that of the time signal] and to wind it up preferably at the same time each day, and in submarines that function was carried out by the wireless office staff which had the chronometer trusted to their care.


Returning to meridians which start and finish at the poles passing through the equator, the thought of a neat pattern emerging [rather like the segments of an orange] should not be considered. In fact, the resultant pattern is nothing less than an asymmetrical mess sometimes with huge deviations from what one might expect.  This came about when countries/territories quite naturally wanted all their territory within the same time zone and many had extended outlaying and thus divorced islands, causing several exaggerated ziz-zags across the Mercator projection or in some cases to what is considered by many the more accurate projection shown on a Peters World Map which represents countries accurately according to their surface areas.  Moreover, the publishers of the Peters, the Oxford Cartographers [www.oxfordcarto.com] state that traditional maps like the Mercator Illustration, have tended to show countries incorrectly in proportion to one another, to the advantage of the European colonial powers, while the southern continents [Africa, South America, Australia] are shown far too small. I recommend the Peters to you, and in some cases certain academic bodies prefer and use it as an educational tool in lieu of the Mercator maps. 

Amen.  Happy time keeping, and remember that is was as long ago as 1970 [fortyseven years as I write] that UTC was authourised so why are you still keeping GMT ?