…Signal box with a difference | Märklin 456

456 “Switch tower with built-in whistle” shown on page 31 of the 1951 Märklin catalogue. Priced at £6-17s-6d, roughly half the price of the 452G crane, or five times that of the electric bell.

Märklin has produced many functional accessories over the years such as level crossings, turn tables and cranes, but the most innovative and endearing of them all must surely be the No. 456 whistling signal box.

First released in 1949, it was in production for five years in only one version. Its relatively short production run and the comparatively high price (equivalent to the RSM800 engine) both contributed to it being a rare and sought after item today, one that had been on my wish-list for quite some time.



Disguised by a (then) modern signal box made of tin plate is the mechanism that produces the whistling sound. Powered by a typical Märklin all-power motor, it is unique in that it is not reversible. Unlike any other motor, its field magnet contains only one coil. The motor drives a fan, while the solenoid opens and shuts the vent cover on the top.



I was lucky enough to win an auction to obtain this example for a very good price. It came to me in the state shown in the above photo. While it did try to work, the motor ran too slow to produce much of a sound. The only thing to do was to dismantle the entire thing and give it a thorough cleaning.

A whole lot of screws hold the cover and its gasket on air tight.



The weighty casting with its cover removed reveals the fan wheel and the S-shaped resonance chamber…



…while on the opposite side, the motor and solenoid are found.



All cleaned and re-assembled, the mechanism is working once again. Note how it is mounted on a rubber base intended to reduce vibrations and noise. Unfortunately, the paper covering the solenoid coil had to be sacrificed in order to retrieve and re-connect the wire.



Seen from the back is the air intake for the fan. The light fitting is functional but not original, as that piece was missing.



At last, it is polished and restored to working order. To see it function, watch the video below.