11 November 2017

X-Ray Specs

































Likely manufactured in the late-1960s but updated in the mid-1980s - the Freed transformer inside is dated August 1969, but the Soderberg anti-collision beacon October 1985 - this Halsey industrial X-ray warning device was used by the United States military. The item bears an affixed metal plate, plus a sticker from the time of its disposal, that together provide valuable information on its origins.

































The Disposal Turn-In Document (DTID) number acts as a unique disposal serial number. The first six places provide the Address Activity Code. FB5587 is RAF Lakenheath. The light was, thus, used by the USAAF. The next four places indicate the date the item was catalogued for disposal. Per the US military's adaptation of the Julian dating system, 9196 is 6 April 1991.















The National Stock Number (NSN) system was standardised by NATO in 1974 to track military assets, although versions of it existed prior. The first four places indicate the Federal Supply Classification Group. FSCG 9905 is for signs, advertising displays and identification plates: even military ID plates have their own ID codes! 00 in the fifth and sixth places indicates the United States.

































Demilitarisation Codes indicate the degree of physical destruction required. DEMIL: A denotes a non-munitions/non-strategic item that does not demand any such. $2,245.63 is understood to be the asking price at disposal in 1991, over £3,000 at 2017 prices. The Federal Condition Code is given as A1 - serviceable without qualification, new/unused.

































Halsey was a trademark of Post Glover Medical Products, of Erlanger, Kentucky. Established in 1938, the company supplied medical items, including X-ray illumination boxes. It still trades, as PG LifeLink. The light would have been supplied via the Warner Robins Air Logistics Center, Georgia, part of the USAAF's Materiel Command.

































Shaped like a truncated pyramid, the device stands 29 inches tall. When switched on the Lucite panels are illuminated from within, and the twin bulbs in the beacon rotate within the red glass housing. Built to operate on US 115v mains, the light has been converted to run on UK 240v, with a new transformer inserted to provide steeped-down voltage for the 28v DC beacon. The original transformer and Hubbell connectors have been left in place, to enable any future reinstatement to the original set-up.

(Many thanks to Steve and Karen Myciunka, of Mullard Magic, for assistance with the item's history; and to various members of the UK Vintage Radio Repair and Restoration Forum for advice and parts.)

16 October 2017

Munrow Sports Centre, Birmingham



The Munrow Sports Centre was constructed in phases as part of the University of Birmingham's expansion plan of the 1950s. It is due for demolition. The athletics track was built in 1951, and now lies three-quarters covered by spoil from construction of the university's new library.

































The multi-building design was created by Chamberlin, Powell and Bon (famous for the Barbican Estate in London), but never fully realised. Phase one, commenced in 1963 and completed in 1966, provided for two sports halls/gymnasia.

































A ramp rose to the reception. The dance studio block was finished with a vaulted roof of repeated shell shapes, a favourite of the practice, formed of concrete and finished with red tiles. Top-lighting was provided by raked forms of an alternative shell shape.

30 July 2017

Ekco Microphone

































This six inch tall moving coil microphone was likely released by Ekco in about 1934, as the design echoes that of their first round radio, the AD65, released that year. There is little available information on these Ekco Bakelite-cased microphones, but it was quite possibly for use with a home recorder.

17 July 2017

Gumball, Rallied

































Bought from a yard sale in Morgantown, Indiana, this XYZ Vending Bulk-PRO triple-head gumball machine is not as old as originally imagined. XYZ Vending was founded in Atlanta, Georgia, in 2003, and closed in 2009. But for $8 one can't go far wrong.

































The cabinet was separated into three parts and the kinks hammered out. It was rubbed down with steel wool, sprayed with two coats of epoxy primer, and then with a number of coats of red lacquer. New cam locks were fitted to the lid, through which the machine is filled, and to the rear door, through which the quarters are collected.

































The triple volume-control and delivery wheel mechanism was stripped down, scrubbed, disinfected, and put through the dishwasher. The metal springs and screws were cleaned-up with a brass wire brush as the mechanism was reassembled.



Each of the three coin mechanisms was cleaned and greased. The brightwork was brought back to life with the aid of fine steel wool. Scratches to the polycarbonate windows were reduced with judicious use of car polish, the 25¢ labels carefully preserved. A pipe stand was sourced, stripped and sprayed gloss black. Just gumballs to add.



21 May 2017

Duluth Aerial Ferry/Lift Bridge



Just 16 transporter - in the States known as aerial transfer or aerial ferry - bridges were built to completion worldwide, between 1893 and 1916. Such structures were very much a European phenomenon; only one was ever constructed in North America, at Duluth, MI. (The Sky Ride built for the 1933 Century of Progress World's Fair in Chicago is often cited as a transporter bridge, but was in fact an aerial tramway.)

































Duluth, at the western end of Lake Superior, is the largest inland port in the world. In 1870-71 the Duluth Ship Canal was cut through Minnesota (alternatively Park) Point, a seven mile long sand spit, in order to provide sheltered docks. Much of the spit was rendered an island. Ferries crossing the canal were unable to operate due to ice in winter, during which an inadequate suspension footbridge would be erected.

































A 1891 competition sought a solution. The city decided to pursue one of the submitted proposals, for a vertical lift bridge designed by John Alexander Low Waddell, but the scheme foundered the following year due to objections from the War Department. Waddell's lift bridge was ultimately built, in 1894, but in Chicago, as the Halstead Street Bridge. A second competition sought a tunnel solution, but this idea sank too.



Meanwhile, between 1896 and 1902, the canal was widened and deepened. Thomas F. McGilvray, City Engineer at the time, inspired by the transporter bridges of Europe, in 1899 sketched one such, although of trussed rather than suspension form, as a way forward. The engineer C.A.P. Turner turned the sketch into a design, approved in 1901. The bridge had a main span of 393' 9", provided for a clearance of 135' above mean high water, and carried a gondola suspended by rigid steel hangers, instead of cables.

































The foundations, built by Hugo & Timms, of Duluth, were completed by March 1902. However, funding difficulties with the American Bridge Company, and then steel supply problems affecting their subsidiary, the Duluth Canal Bridge Company, meant the bridge itself didn't proceed. DCBC's contract lapsed in May 1903.



Construction, by the Modern Steel Structural Company, of Waukesha, WI, finally commenced in July 1904. The first crossing of the gondola, 50 feet long, 30 feet wide, and fitted with tracks so as to be able to carry a loaded tram (streetcar) of 21 tons, took place on 23 February 1905. The crossing took about 1¼ minutes. Load-tested with 65 tons on 24 March, the bridge opened to the public three days later. The first car, an electric Studebaker Stanhope, crossed on 8 April.



However, as was the case with all transporter bridges, increased car ownership and usage rendered the bridge inadequate to demand by the mid-1920s. A redesign was undertaken in 1927 by John L. Harrington, of Harrington, Howard & Ash, of Kansas City. The solution was a lift bridge, remarkably similar to that designed by Waddell, with whom Harrington had once been a partner. The design was approved by the city in February 1927 and in January the following year received the blessing of Congress.



The contract was awarded to the Kansas City Bridge Company in February 1929, and work started the next month. The gondola crossed the canal for the last time on 1 July 1929. The re-engineering involved raising the towers 41 feet to accommodate the deck without compromising the 135' clearance, and strengthening them to carry the additional weight by building additional towers within the old ones. To avoid interruption to shipping, the 900 ton moving deck, counterbalanced by a 450 ton concrete weight in each tower, was constructed in the lifted position.



The converted bridge was first used on 12 January 1930. As ships and boats approach they blow a long-short-long-short signal on their horn, although lifts, which take just a minute, are largely radioed for about 1½ miles out. The signal is copied back by the bridge on its pair of Westinghouse Air Brake locomotive horn sets. There are about five thousand lifts per year. The bridge was added to the National Register of Historic Places in May 1973.

26 March 2017

Venner Time's Right

































Venner is synonymous with time switches: Robert Francis Sidebottom Venner was the electrical engineer who invented them. His business was founded in 1906. It was incorporated in 1911 as Venner Time Switches Ltd, a private company; went public in 1937; and was acquired in 1970 by AMF (American Machine and Foundry Co.) International. Venner's electromechanical time switches provided clockwork back-up to electrically-driven mechanisms, most typically in street lighting. The company was also responsible for the initial installation at pedestrian crossings of very many of the UK's Belisha beacons.

This Venner Type 99567 is from the 1930s, and is wholly clockwork. A knurled nut in the centre of the clock face can be loosened and the 'In' (on) and 'Out' (off) time settings adjusted. The clockwork rotates the mechanism and the pegs attached to the time markers throw a cam. A circuit is formed by the cam dropping copper prongs into Bakelite pots of conductive mercury. The work on this example has been limited to stripping and painting the case, and winding the clock.

04 March 2017

Karan Anne Porter

































Thursday 4 March 1965 to Wednesday 4 February 2009.
Photograph: Fulham, March 1991.