The B and D Series WABCo Train Horns
WABCo also produced B Series train horns, only that these horns are hard to come by. Among the variety of train horns in the B Series are the B-6 horns and the B-7 horns. The B-6 horns appeared in the market for a very short period of time only. It has been thought that these B-6 horns came out only before the B-7 and A-6 horns were introduced. It has not been made exactly clear how B-6 horns sounded, although they are thought to have carried the same sounds as their A-6 counterparts, A and C.
The B-7 train horns, on the other hand, are not at all like the B-6 train horns. The B-7 horn does not use a weighted diaphragm, but instead utilizes a single stainless diaphragm. The housing of the diaphragm, as well as its foot mounting, belongs to a single, uncomplicated assembly. The bells are securely fastened into the base with a pin. The bells of the B-7 horns come in four sizes, each sounding a different tune. The B-7-21 is tuned to an A below middle C, the B-7-25 is tuned to a middle C, the B-7-30 plays a tune between a D and a D#, while the tune of the B-7-36 is somewhere between an F and an F#. B-7 horns are often used in conjunction with the E-2B train horns.
The D Series WABCo Horns
The D Series train horns are smaller than the other series of train horns produced by WABCo. One of the models of the D Series is the D-5 horn. These horns have long and short bell sizes, with the longer bell playing an F, and the shorter bell playing a G. The D Series horns are similar in appearance to a truck horn. These train horns also have a diaphragm housing unit with a back cap that is attached to its back. The same single-disked diaphragm is used, whether the bell is a short one or a long one. The D-5 horn is unique in that there is an adjustable screw that influences the operating pressure of the horn. The D-5 horns appeared in the market at about the same time that the A-1 horns did.
Another model of the D Series WABCo train horns is the DD-5 horn. This train horn is a combination of two bells, with the shorter horn mounted in vertical position above the longer horn. The DD-5 can play an F and a G#. The DD-5 horn is not exclusively produced by WABCo. The company has granted permission to other manufacturers to produce the DD-5 horn. One of the companies that have come up with models of the DD-5 horn is the Bendix-Westinghouse.