The morning journal-courier., 1908-07-09


 enters the second block the color of the second miniature section of the indi- cator turns red and as the tail of the train leaves the first block in the tun- nel the representative space on the in- dicator gows again with green light.
 In this way the progress of the train Is shown like n glowworm of ruby hue descending the Incline at the Brooklyn end to the center and steadily climbing section by section on tho up grade to New York Soon the last section of the indicator burns red and moment later the train runs into the station, clears the block, and the green light, again showing on the tiny block section. proves that the train is out NF
 The whole arrangement appears in the face of 1t to be simplicity itself, and like most other effective devices 1t Is in sense quite simple, but there are some details which have been worked out in connection with the de- vice which have required considerable skill and judgment. The ordinary track circuit carries an alternating current of about seven volts. This current op- crates an A. C. relay which governs the movement of direct current re- lay, which opens and closes a D. c. circuit This direct current is used to operate the electro pneumatic mechan- ism which moves the automatic stop at each of the signals On this D. c. cir cult is another relay, which, according to the arrangement for the device, makes and breaks the 60-volt alternat- ing current which is used in lighting the lamps in the indicator and in the signals in the tunnel
 The glow lamps of the indicator are, if one may So say, turned in unison with the home signals of every block so that when block Is clear the green light of the actual block signal is faith fully reproduced in the green color of the indicator band, which represents that block When the real block Is oc- cupled the home signal shines red and the indicator block, only few inches | long. glows with the same color, This device ie in sense very perfect sci- entific instrument The spectroscope reveals to the trained eyes of science the presence or absence of certain sub 1 stances In the glowing atmosphere of | the sun, and SO this tunnel spectro- scope makes visible by the attenuation of its coored lights the entrance, pas sage and disappearance of moving | train.
 i The inception of this unique device Is | due to MT. Frank Hedley, general man. ager of the Interborough system, and I the details have been cleverly worked out by Mir, ] M Waldron, the signal ! engineer of the company The device is | placed above a telephone switchboard where terminate the wires of about sixty telephones which are distributed through the tubes at a distance of i about 300 feet apart. Chemical Are ex- tinguishers are also placed at each telephone station in the tunnel and a ] city water main passes through each tube with hydrants every 300 feet, each supplied with 200 feet of fire hose. [ Not only is there a home and eau. tlon signal at the entrance of every block in the tunnel, each equipped with an automatic stop similar to those used on the express tracks of the subway ]. but the blocks are proportioned in ac. cordance with the grade and the esti. mated speed of trains either under power of coastng The longer blocks are necessarily near the lowest DOT tons of the tunnels
 The indicator in the dispatcher's of fee can thus reveal the particular blocl occupied by q stalled train and would give such visible information as ma, enable the dispatcher to block the en trance of the tunnel for all othel trains, while the crew of the stalled train would never find themselves more than l50 feet away from the near est telephone by which the ear of tht dispatcher could be reached. A sigma out of order In the tunnel or burned out glow lamp in the indicator readl, becomes apparent With the correc working of the whole tunnel apparatus one may almost say that sight ant hearing are extended through the tube and are in this way given to the ma, in charge whose duty 1t is to watcl over the movement of the trains a. they pass below the bed of the Eas river between the sister cities Brook lyn and New York