~~ Siqnalinq and Communications

Unit lever interlocking machine has controls for 10 crossovers, 14 switches, 45 signals and 1 movable point frog

Interlocking Consolidation: Three Into One at Baltimore

Track changes and interlockings modernized at the B&O's Camden ·street station where traffic includes 55 passenger and 170 freight trains every 24 hours as well as hundreds of switching movements

A NEvV ALL RELAY INTER­ joined at the throat of the depot; run north H~ miles to Nit. Royal sta­ LOCKING, replacing three previous and an electric interlocking at the tion where it turns east toward interlockings, was recently placed wye at Bailey. The signals were, and Philadelphia and New York. At in service at the Baltimore & Ohio's are the B&O's standard color-posi­ Bailey, a double-track line runs east downtown passenger station at Cam­ tion light type. Upper level tracks to the B&O's yards and docks at den street in Baltimore, 11d. The are used by passenger trains originat­ Locust Point on the Patapasco River. former signaling and interlockings ing or terminating at Baltimore. The From the west end of Howard street included a mechanical· interlocking lower level tracks are used by tunnel to a point approximately 3 with facing-point locks on the through trains. miles east, there is a very heavy switches and crossovers of the five ascending grade. Trains operated by upper level stub-end tracks in the Electrification Ends steam locomotives required a helper. depot; electric switch machines on A city ordinance, of the anti-smoke the switches and crossovers on the The double-track mainline enters variety, required that eastward lower level two main tracks at the the city from the south and swings trains be operated by electric loco­ west end of Howard street tunnel; east to Bailey where it turns north motives. Therefore, until the advent hand-throw switches where the up­ towards Camden station. Here the of dieselization, all eastbound trains per-level and lower-level tracks line enters Howard street tunnel to operated by steam locomotives were

JUNE, 1956 RA ILWA Y SIGNALING and COMMUNICATIONS 23 moved and the track layout simpli­ fied by removing some switches and crossovers. New GRS model 5C elec­ tric machines were installed and the color-position light dwarf signals were relocated. In the simpliflcation of the lower level interlocking, the ~'motor pen" track was removed, which also in­ cluded the removal of some switches and crossovers. Power switches and crossovers were installed at the Hamburg street throat where the upper and lower level tracks con­ verge, replacing hand-throw switches previously in service. New Unit-Lever Machine The control machine has a black panel with white lines representing Smashboard controls are interconnected through signal controls the tracks with white indication lamps being lighted to show track pulled through the Howard street needed repairing. Thus it was de­ occupancy. Switches are operated tunnel to Waverly by electric loco­ cided that an effective solution by toggle levers, the normal position motives, operating on 660 de, from would be the installation of a mod· being down. A switch point indi­ a third rail. After full dieselization ern, all-relay interlocking with a nevw cator on the track diagram forms a in 1953, the "motor pen" track and control machine in a new tower at continuous white line with the track other facilities for the electric loco­ Hamburg street, known as HB. showing the route as lined by the motives were no longer required. Bailey interlocking at the wye was operator. Above each switch lever is In addition, the mechanical inter­ unchanged in the new plant, except a red lock lamp and ~n amber out­ locking on the upper level was in that the controls of the switches and of-correspondence lamp. The signal need of repair or replacement. Al­ signals were brought into the new control knobs are the push-pull-turn though "BY" interlocking was in control machine. The upper level type. To clear a signal after the good condition, the tower itself mechanical interlocking was re- route is lined, simply requires the

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I ~ " 1,, D RIVERSIDE LOCUST POINT-

RAILWAY · SIGNALING ond COMMUNICATIONS JUNE, 1956 operator to push the signal knob. The indication lamp in the barrel of the knob is lighted red when the knob is pushed, but tm·ns white when the signal clears. The red lock lights over the switches are also lighted, as the train passes the sig­ nal, the signal knob lamp is ex­ tinguished, as are the white track occupancy lamps when the train leaves a track ciTcuit. Sectional route release locking, as well as time lock­ ing are employed. To facilitate various switching moves, particularly where head-end cars are added or removed from trains, the call-on aspect has been employed. For example, to clear sig­ nal 117 to allow a switch engine to put a car on a train over switch 118 Switch machines operating on 11 0 volts d.c. have outboard brakes reversed, the operator turns the 117 signal knob white dot down and Therefore, traffic levers, on the con­ this tunnel. In order to obtain in­ then pushes the knob. This action trol panel, are for the tracks con­ creased clearance for freight trains, will cause signal 117 to display the necting these interlockings, and sig­ a third track in the center of the call-on aspect (two lunar white nals, of course, cannot be cleared tunnel is used as gauntlet. This re­ lights inclined 45 deg., lower quad­ from one interlocking into the other quires extra power switches and rant. until traffic direction is established. aspects on signals. Before signal141 In addition to this traffic locking, or 143 can be cleared the smash­ Special Clearing for Switching special controls were established on board must clear. the signals governing eastward train A bell is provided to indicate the Signals 87 and 97 can be cleared movements into Howard street tun­ occupancy of the approach circuits against each other to the lunar white nel. After traffic direction is estab­ to signals 11, 13 and 43, as well as aspect to provide for switching lished, the operator cannot clear sig­ the track circuits in Howard street moves over crossover 88 normal. nals 141 or 143 for movement into tunnel. This is done by pushing one signal the tunnel until the operator at the The new brick tower at Hamburg BALTIMORE (CAMDEN STATION)

147 ;('HOWARD STREET TUNNEL ~ -- W.B. MAIN 143~-;,.::-...~1 4}:~J;[email protected]_.-_-_-_:::.::.: : ------E:S:'"MAIN ..::::_----- 14 149 - ._,;;;;;;;;;=;::::;:;:;::::;:;:;;;:;;;::?": TO NORTH AVE . ~------~'~4~1~ EAST LEGE NO TRAFFIC LEVERS = 77t--+ w w ...J

knob and then the other. The signals other end of the tunnel clears a sig­ street has two stories, with the relay, are returned· to stop by pulling the nal for movement out of the tunnel. batterv and maintainer's office on the knobs. These same special clearing This procedure works in reverse for ground floor. Also on the ground provisions are provided for on sig­ weshvard train movements. In addi­ floor is a wing containing the Cam­ nals 95 and 103 with crossover 96 tion to these controls, signal 141 and den street yardmaster's office. The normal. 143 controls are interconnected with new control machine is on the sec­ The three junctions at the Bailey controls of smashboards at the tun­ ond floor of the tower. The relav and wye are treated as separate inter­ nel entrance. Passenger trains gen~ battery rooms in the tower are for lockings as are Hamburg street and erally operate right-hand running on the Hamburg street interlocking the upper and lower level tracks. conventional double track through (Continued on page 56)

JUNE, 1956 RAI LWAY SIGNALING and COMMUNICATION S 25 B&O Interlocking throughout. Track wires are No. 9 solid copper. All wire and cable was (Continued from page 25) furnished by the Kerite Company. control equipment. Twelve cells of Exide 120-a.h. storage battery are New Crossing Protection split for controls and the interlock­ ing machine operation. Another six As part of the Camden street in­ cells of 120-a.h. capacity are for lo­ terlocking modernization, short-arm cal circuits, and 55 cells of 80-a.h. gates with flashing light signals are provide power for the 110-volt d.c. being installed at Warner and switch machines. These are model Ridgely street crossings. The cross­ 5C with the outboard brake. In the ing protection equipment controls change over to the new interlocking, are being interconnected with home the old single rail a.c. track circuits signal controls so that a train stop­ were replaced with conventional d.c. ping on an approach sect-ion, but track circuits with two-ohm track re­ short of the crossing, will not put the lays. Trenchlay cable was used gates down if the home signal is not

Cable terminations in "HB" tower

air depolarized AD PRIMARY CELLS Save users LABOR, TIME, MONEY Maximum discharge rates: 1.0 amp. continuous 2.5 amp. max. intermittent Approximately one gallon of water for 2500 watt hours. No washing of jars. No mixing of caustic. Only one stores item.

Railway track circuits- light signals-electrical aids to navigation, Telephone exchange batteries, etc. ad 608a \

Rectifier panel is in battery room Argentina-LE CARBONE LORRAINE, Erezcano 3051/53 Buenos Aires, Argentina Belgium-LE CARBONE S.A.B., 124 B.d. du Jubilee, Brussels, Belgium Brazii-CARBONO LORENA S.A.-Rua Barao, ltapetininga 273 Sao Paulo, Brazil clear. At Warner street special "E" Canada-CIPEL (CANADA) LIMITED-Vafleyfield, Quebec, Canada and "W" dwarf signals will govern England-LE CARBONE (GREAT BRITAIN) LTD.-Portslade, England movements on the switching lead France-CIPEL, Argenteuil (S&O) France over the street. When the gates are Germany-CARBONE A. G., Bonames, Frankfurt/ Main, Germany down, the dwarf signal will display ltaly-SOCIETA "PILE CARBONIC," via Rasori 20, Milan, Italy lunar white (two lamps lighted, 45 Spain-CIPEL, Juan Bravo, Madrid, Spain deg. lower quadrant). If the gates Sweden-SVENSKA A.B. LE CARBONE, Sundbyberg, Sweden are not down, the signal will display I.J S.A.-THE CARBONE CORPORATION, Boonton, N.J. two horizontal red lights (Stop). A. L. Jordan, signal engineer, di­ rected the engineering and installa­ sales representatives throughout the world tion work. The major items of signal­ ing equipment was furnished by the General Railway Signal Company.

56 ' RAILWAY SIGNALING and COMMUNICATIONS JUNE, 1956