Duplex

Duplex may refer to:

Entertainment

Science and medicine

Technology

Other

Duplex!

Duplex! is a children's music band from Vancouver, British Columbia, Canada that claims influences from urban folk to punk rock. The members range in birth years from 1967 to 2002; both toddler Abe Caruso and noted Canadian musician Veda Hille played on the debut album.

Members

Ages given are as of the band's formation in 2005.

Discography

Their first album, Ablum by Duplex!, was released in 2005 on the Mint Records label. Their second album, Worser, was released in 2009.

See also

External links

Duplex locomotive

A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive. The concept was first used in France in 1863, but was particularly developed in the early 1930s by the Baldwin Locomotive Works, the largest commercial builder of steam locomotives in North America, under the supervision of its then chief engineer, Ralph P. Johnson.

Prior to this, the term duplex locomotive was sometimes applied to articulated locomotives in general.

Drawbacks of the 2-cylinder locomotive

While the side rods (UK: coupling rods) of a locomotive can be completely balanced by weights on the driving wheels since their motion is completely rotational, the reciprocating motions of the pistons, piston rods, main rods and valve gear cannot be balanced in this way. A two-cylinder locomotive has its two cranks "quartered" — set at 90° apart — so that the four power strokes of the double-acting pistons are evenly distributed around the cycle and there are no points at which both cylinders are at top or bottom dead center simultaneously. A four-cylinder locomotive can be completely balanced in the longitudinal and vertical axes, although there are some rocking and twisting motions which can be dealt with in the locomotive's suspension and centering; a three-cylinder locomotive can also be better balanced, but a two-cylinder locomotive only balanced for rotation will surge fore and aft. Additional balance weight — "overbalance" — can be added to damp this, but at the cost of adding vertical forces, which are known technically as "dynamic augment" and colloquially as "hammer blow". This can be extremely damaging to the track, and in extreme cases can actually cause the driving wheels to leave the track entirely. The heavier the reciprocating machinery, the greater these forces are, and the greater a problem this becomes.