Poured Sockets
I have just finished reading your article “Poured Socket Connections” in the Winter 1976 issue. Having had considerable background in poured socket connections I agree with your article almost to the letter. However, in your list of criteria for visual inspections, I would like to call your attention to one inconsistency which could cause considerable confusion on European-built tramways and chairlifts.
In category 3 of your criteria, which covers the “dimpling” effect produced by a properly poured socket, it should be noted that the “dimpling” effect will be quite evident if the socket was poured with 99 per cent pure zinc. In some cases, however, the European lift manufacturers do not use pure zinc for casting sockets. They use special metal alloys developed especially for socket casting. The problem lies in the fact that zinc has a shrinkage of 1.4 to 1.6 per cent of its volume, which will produce the “dimple” effect. The European alloys have a volumetric shrinkage of only 0.3 to 0.5 per cent which will not produce the “dimple” at all, or in any case, make it very hard to detect.
I believe that both are acceptable socket casting methods but the above characteristics should be recognized, especially when conducting a visual inspection.
Robert E. Ficker
Snowbird, Utah
Sir:
Howard Anderson’s article on poured socket connections in the Winter issue of SAM was timely and of interest to all aerial tramway and ski lift operators.
May I correct an erroneous reference in the footnote of that article? In November of 1974 I circulated to Forest Service personnel and others of our industry an information bulletin on the subject “Wire Rope End Connections of the Poured Socket Type.” The bulletin had attached several articles from “International Aerial Tramway Review” land an excerpt from one in “Elevator Lift and Ropeway Engineering,” Full credit was given the authors and publications.
I do not consider myself an authority on poured sockets and did not write on the subject for publication in United States or foreign trade journals.
Charles F. Dwyer
USDA – Forest Service
