measured mile at Newbiggin

Shipping from Berwick to Amble

measured mile at Newbiggin

Postby Terrysummerson » Wed Sep 24, 2014 4:20 pm

I saw this article in the Shipbuilder on the measured mile towers in Newbiggin
The Newbiggin Measured Mile

OVER the years, the measured mile on the North East Coast has been at Hartley and has been the subject of considerable criticism from the shipbuilders of that area. In order to get adequate depth and a good run, it has been necessary for ships to stand out to sea a considerable distance and the traditional bad visibility of the North Sea has interfered with the proper observation of the towers. Added to this, of course, was the need, at times, for running trials in distinctly unfavourable weather and unpleasant seas. For this reason important trials have often been run on the Clyde at Skelmorlie, and more recently at the double mile run off the Isle of Arran.
So far as the North East Coast is concerned, nothing much can be done about the general weather conditions but some time ago it was decided to move the measured mile course to a more favourable situation and at the same time to experiment with the use of neon or
other lights which have considerable fog penetration.
The task of .maintaining this measured mile course falls on the North East Coast Institution of Engineers and Shipbuilders and the matter was discussed at some length in the annual report of the Council of which we gave a summary in our issue of October 20.
Accompanying this report were some illustrations of the new course and some further details of it as now established. We are indebted to the Institution for the material which they have placed at our disposal from this report.
Many ship trials have been carried out on this course recently, a large number of them taking place during hours of darkness and the projector lights on the marking towers have been found very satisfactory. They have enabled trials to be conducted at distances up to 11 miles from the coast in 40 fathoms depth.
The measured mile consists of four tower sites situated in the neighbourhood of Newbiggin as shown in the extract from the Admiralty chart on the opposite page. From the sea the limits of the measured mile are indicated by either the northern or southern pair of towers, coming into line respectively. The exact siting of the four towers was
finally checked by the Admiralty Hydrographical Department.
Each front tower (as seen from the sea) has a substantial marking plate painted black and two projector lights and each back tower has two marking plates and two projector lights. The arrangement of these can be seen from the accompanying illustrations. The arrangement of marking plates as seen from the sea gives the effect of the single front plate "filling the gap" between the two back plates. The principle was developed from model tests and in practice.
The lights are not specifically for night use but are used also for sighting during the day when visibility is inferior or when trials are to be carried out some distance off-shore in deeper water.
The lights are switched on and off at a central control point in the fan house of Newbiggin Colliery. This place was chosen because it is manned continually and has a telephone installed. The actual switch closes a G.P.O. relay circuit which switches the lights at each tower (or at the common sub-station in the case of the northern tower) by
means of a relay and contactor.
The foundations of the towers are concrete pyramids connected by reinforced concrete beams underground.
The tower construction is throughout of bolted galvanised steel. Each tower has an access ladder to the top with platforms at every 50 ft. and at each marking plate.
As the area is a mining district, each tower is constructed with a special base so that if mining subsidence were to take place causing the tower to tilt, it could be restored to its vertical position. The projector lights are General Electric Co. F5724 floodlights. These floodlights can be fitted with different sizes of lamps, the three most suitable being as follows: —

Maximum
beam Beam

Type Wattage angle candle-power

General service 1,000 28° 128,000
General service 1,500 28° 210,000
Class B2 .. 1,000 12° 325,000

The beam candle power available is of the same order as that of the most powerful lighthouses on the North East Coast. Up to July, 1949, Class B2 lamps were not available and 1,500 watt general service lamps were used. During the course of July, however, 1,000 watt Class B2 lamps were fitted in the upper projectors. It is not proposed to fit the Class B2 lamp throughout until experience has been obtained with its narrower, if more powerful, beam as compared with that of the general service lamp.
The general appearance of the towers is shown in our illustrations. It will be noted that the back towers have two marking plates and the front have one plate. The towers are designed with a factor of safety of 2.5 for an assumed wind loading of 30 Ibs. per sq. ft on the marking plates and 4 times the members of one tower face.
General particulars of the towers are: —

Tower No. 1 2
(S.W.) (S.E.)
Height 150ft. 132ft. 6in
Extra height of
top mast 30 ft. 30 ft
Base width 24 ft. 24 ft.
Total weight of
steelwork 11.5 tons 8.5 tons

Tower No. 3 4
(N.W.) (N.E.)
Height 150 ft. 150 ft.
Extra height of
top mast 30 ft. 30 ft
Base width 24 ft. 24 ft.
Total weight of
steelwork 11.5 tons 9 tons

The height of the towers is such as gives all the marking plates a "sky background" as seen from at sea. The lower illustration opposite gives a view of two of the towers from the sea.
The towers and foundations were designed and erected by Riley and Neate, fabrication of the towers was by Palmers Hebburn Company, and the whole of the work was done under the supervision, and to the preliminary designs and survey of the consultants,
Merz and McLellan.

newbiggin1 copy.jpg

newbiggin2 copy.jpg
Terrysummerson
 
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Re: measured mile at Newbiggin

Postby E28 » Fri Jan 05, 2018 8:05 pm

Surely the Newbiggin structures were the most elaborate ever constructed for such a purpose with little likelihood of any seafarer unable to see them. Maybe it was also used by planes, which also measure speed in knots. They would also have been most convenient for the Luftwaffe

But, i ask, did it succeed with any ships from the East coast yards utilising this mile. It had replaced the much older Hartley mile after much criticism that it was difficult to see let alone use and duly demolished.

Most Tyne built warships from the 1930's appear to have used the St Abb's mile just over the border for full power trials which implies Newbiggin was almost exclusively Merchant where speed was measured for economy at varying power.

Please correct me if that is false.
Thats all folks. Sean.
E28
 
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Re: measured mile at Newbiggin

Postby Dennis Maccoy » Fri Jan 05, 2018 9:05 pm

The Newbiggin mile was in regular use by Swan Hunter until the eighties. Naval preference for St Abb's might be related to water depth - the faster the ship the greater the depth required to ensure a reliable result - if the runs take place in water that is too shallow misleadingly high speeds can be recorded. Merchant ship trial speed over a measured mile was generally assessed to prove contract compliance - power-economy relaionships were generally assessed on longer endurance trials.
Regards, Dennis.
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