Pacific Electric 4
Pacific Jct., IA 2
Pacific Jct., IL 1
Pacific Jct., MT 2
1961 News Briefs. 1961-06 718.3 KB
1962 News Briefs. 1962-01 979.5 KB
Packerton, PA 1
1965 News Briefs. 1965-07 793.4 KB
Paddington, Manitoba 1
1955 News Briefs. 1955-08 801.6 KB
Paducah & Illinois 1
Paducah, KY 2
Page Ave., St. Louis, MO 1
Painesville, OH 1
1955 News Briefs. 1955-08 801.6 KB
Palestine, TX 1
Palmer Lake, CO 1
Pana, IL 2
Panama 1
Panhandle & Santa Fe 1
1963 News Briefs. 1963-01 971.6 KB
Paola, KS 2
1955 Both ways on both tracks with CTC 765.0 KB
1962 News Briefs. 1962-07 509.0 KB
Paoli, PA 4
Paradise, MT 2
1965 News Briefs. 1965-01 2.0 MB
1966 News Briefs. 1966-01 1.4 MB
Paralta, IA 1
Paris Transport 1
Paris, France 3
Park City, KY 1
1964 News Briefs. 1964-08 827.3 KB
Park Jct., PA 2
Parkersburg, WV 5
Parkesburg, PA 1
Parkway, IL 1
Parma, OH 1
1964 News Briefs. 1964-09 899.1 KB
Parsons Yard, OH 1
Pasco, WA 2
passenger reservations 1
passenger terminals 1
1950 Passenger Terminal Signals 993.8 KB
passenger trains 1
1947 Signaling Order Issued by ICC 533.4 KB
passing sidings 1
1940 "Running" Passing Tracks 1.1 MB
Patenall, F. P. 6
Patterson Creek, WV 1
1961 News Briefs. 1961-07 654.1 KB
Paulina Jct., Chicago, IL 1
Paulista 1
Pauls Valley, OK 1
Pavonia, NJ 1
Peach Creek, WV 1
pedestal signals 1
1947 How Low Is a Dwarf? 438.7 KB
Pee Dee, SC 2
1962 News Briefs. 1962-05 831.1 KB
1962 News Briefs. 1962-06 980.1 KB
Peekskill, NY 1
1962 News Briefs. 1962-02 1.4 MB
Peerless Manufacturing 1
Pekin, IL 3
Pelham Bay Line, New York, NY 1
pendulum type code transmitters 1
Penn, Philadelphia, PA 2
Pennock, MN 1
Pennslvania 1
Pennsylvania 204
1951 "Central" Increases Safety at Highway Crossings in Dayton 1.0 MB
1940 11,000-Ft. Coded Track Circuits 13.6 MB
1925 A movement was begun 604.7 KB
1933 A New Deal on Train Control 639.0 KB
1911 A Summary of Signaling Practice 3.6 MB
1925 A. H. Rudd Discusses Train Control at Philadelphia Engineers' Club 2.8 MB
1949 A. H. Rudd obituary 947.2 KB
1937 A. H. Rudd Retires 1.6 MB
1929 Adjustment of Clockwork Time Releases 1.4 MB
1937 Approach Indications to Train Order Signals 4.2 MB
1929 Are Automatic Signals on Sidings Justified? 1.6 MB
1921 Aspects of the Position Light Signal 203.5 KB
1951 B&O Installs Modern Interlocking 871.3 KB
1936 Bad Collisions on Best Railroads 2.5 MB
1915 Beam-Light Signals on the Pennsylvania 318.8 KB
1929 C&EI Derailment and Collision at Chicago 755.9 KB
1936 Cab Signaling 7.8 MB
1933 Call-On Signals 930.2 KB
1933 Call-On Signals (editorial) 1.0 MB
1946 Carryphone on the Pennsylvania 1.5 MB
1934 Centralized Traffic Control Installed on the Alton 1.1 MB
1931 Centralized vs. Remote Control 1.2 MB
1937 Changes on the Pennsylvania 1.6 MB
1933 Checking the "D" Relay 440.2 KB
1947 Choice of Interlocking Control Machines 266.5 KB
1931 Circuit for Signal Demonstration 490.2 KB
1935 Coded Track Circuit Signaling on the Pennsylvania 9.8 MB
1956 Conelrad – A Civil Defense Measure … How Some Railroads are Participating 4.1 MB
1947 Construction of Towers 213.3 KB
1933 Control of Signals at Dual-Control Switches 891.3 KB
1929 Control Schemes for Take-Siding Indicators 360.3 KB
1934 Crossing Gate With Light Signals Installed at Railroad Crossing 1.0 MB
1955 Crossing protection for 16 streets 371.1 KB
1947 Crossing Protection in Gary, Indiana 1.6 MB
1952 CTC Machine Hangs High But Trains Run 704.9 KB
1947 CTC Saves Train Time on the Pennsylvania 1.5 MB
1927 Derail Failure Results in Collision on Crossing 995.6 KB
1931 Derails in Passing Sidings 1.1 MB
1921 Derails: Are They Good or Bad? 350.6 KB
1937 Direct-Wire or Coded Circuits 1.3 MB
1926 Directing Trains By Signals 1.9 MB
1936 Double-Caution Signaling 3.4 MB
1927 Electric Locking Protection at Interlockers Operated Without Derails 1.1 MB
1962 Electric Switch Lamp Lighting Helps Reduce Operating Expense 661.7 KB
1920 Electro-Mechanical Interlocker at Sunbury, PA 538.5 KB
1915 Emergency Suburban Traffic 252.9 KB
1937 Ends of Double Track Controlled by CTC 12.4 MB
1945 Extensive All-Relay Interlocking Features Plug-In Relays 5.6 MB
1935 Facing Point Locks on Switches 3.2 MB
1915 First Position Light Signal Installation 580.6 KB
1936 Flood Damage to Signaling 5.0 MB
1922 Four Position Signaling 859.8 KB
1933 Four-Position Dwarfs 1.5 MB
1935 FPL Adjustment on Spring Switches 1.3 MB
1941 Frank Rhea (obituary) 1.0 MB
1938 Grade Signal Markers 596.4 KB
1950 High Speed Turnout Signaling 2.3 MB
1947 Highway Crossing Protection Installed by Several Railroads in Gary, IndianaR 1.2 MB
1947 How Low Is a Dwarf? 438.7 KB
1946 ICC 50-MPH Signal Hearing 6.9 MB
1950 Increasing Use of Carrier 1.3 MB
1944 Inductive Train Communication 3.9 MB
1935 Installation of Bond Wires 4.0 MB
1936 Interlocking and Remote Control on Erie 18.9 MB
1938 Interlocking Changes on the Pennsylvania 4.9 MB
1961 Interlocking Costs 293.9 KB
1950 Interlocking Plant Horns 2.3 MB
1956 Interlocking Relays 3.9 MB
1952 Interlockings Modernized at Three Railroad Crossings 974.7 KB
1937 J. C. Mock Retires 1.4 MB
1920 Largest Saxby & Farmer Machine in the United States 1.6 MB
1935 Letter to the Editor- Comment on Multiple Aspects 1.5 MB
1920 Light Signals to Supplant the Semaphore 7.0 MB
1925 Light Signals, Color, Position, or Color-Position 1.5 MB
1933 Lock Releasing 469.9 KB
1936 Lost Motion in Locking 3.0 MB
1954 Loudspeakers and Interlocking Improve Yard Operation 4.7 MB
1949 Main Line Crossovers 2.4 MB
1938 Milwaukee Rehabilitates Large Plant 8.0 MB
1951 Modern Interlocking on the Norfolk & Western 710.2 KB
1931 Movable Bridges and Yard Entrance Layouts Controlled from One Cabin 4.5 MB
1936 New Electro-Pneumatic Plant On Pennsylvania at Newark 23.9 MB
1947 New Interlocking at Bellevue, Ohio Protects Crossings of Four Railroads 997.9 KB
1930 New Interlocking on Pennsylvania at Harrisburg Replaces Three Old Plants 2.3 MB
1937 New Signaling on Pennsylvania 1.0 MB
1916 New York Central and Pennsylvania Change Colors 220.3 KB
1955 News Briefs. 1955-08 801.6 KB
1961 News Briefs. 1961-07 654.1 KB
1961 News Briefs. 1961-12 971.1 KB
1962 News Briefs. 1962-02 1.4 MB
1962 News Briefs. 1962-03 1.1 MB
1963 News Briefs. 1963-01 971.6 KB
1963 News Briefs. 1963-10 518.0 KB
1964 News Briefs. 1964-05 1.0 MB
1964 News Briefs. 1964-11 791.4 KB
1965 News Briefs. 1965-01 2.0 MB
1965 News Briefs. 1965-02 1.9 MB
1965 News Briefs. 1965-04 1.5 MB
1965 News Briefs. 1965-06 1.2 MB
1965 News Briefs. 1965-07 793.4 KB
1923 News of the Month (October 1923) 1.9 MB
1941 Non-Stop Permissive Signals 2.8 MB
1915 North Philadelphia Interlocking 828.9 KB
1937 Ohio Flood Damages Signaling 9.7 MB
1931 Oil or Electric Switch Lamps? 1.8 MB
1935 Operating Long Switch Points 2.4 MB
1927 Organization of Railroad Signal Departments 3.9 MB
1941 P. M. Gault obituary 1.2 MB
1937 Pennsylvania CTC Installation 7.0 MB
1931 Pennsylvania Cuts Over Large Interlocking Plant Without Delaying Traffic 2.6 MB
1938 Pennsylvania Electrification Signaling 5.3 MB
1951 Pennsylvania Exhibits Speed Control 512.5 KB
1928 Pennsylvania Installs an Interlocking Without Derails 2.3 MB
1929 Pennsylvania Installs APB Signaling on 86 Miles 3.7 MB
1930 Pennsylvania Installs Centralized Control on 30.3 Miles of Single Track 1.7 MB
1940 Pennsylvania Installs Centralized Traffic Control On 69 Miles of Line 13.1 MB
1928 Pennsylvania Installs Code System of Train Stop with Signaling 5.7 MB
1941 Pennsylvania Installs CTC at Louisville, KY 4.9 MB
1944 Pennsylvania Installs CTC On 53 Miles of Busy Single Track 8.5 MB
1929 Pennsylvania Installs Interlocking at Lancaster, PA 3.6 MB
1952 Pennsylvania Railroad Installs Large Modern Interlocking at Passenger Station in Philadelphia 1.6 MB
1940 Pennsylvania Testing Procedure 16.6 MB
1940 Pennsylvania Testing Procedure (Part II) 8.6 MB
1940 Pennsylvania Testing Procedure (Part III) 8.9 MB
1930 Pennsylvania Uses Remote Control for Switches 1.1 MB
1935 Pole Lines for Automatic Signaling 1.6 MB
1931 Preparation of Signal Circuit Plans 2.0 MB
1935 Preventing Unnecessary Operation of Highway-Railroad Crossing Signals 4.3 MB
1943 Progress in the Use of Coded Track Circuits 1.6 MB
1921 Proposed Modification of Stop-and-Proceed Rule 1.4 MB
1931 Protecting CTC Switches 2.9 MB
1927 Protecting Main Line Switches 486.2 KB
1941 Protection at Hand-Thrown Switches in CTC Territory 1.6 MB
1925 PRR construction (Lima, et al): News of the Month (July 1925) 675.8 KB
1965 PRR converts two hump yards 634.6 KB
1965 PRR upgrades yard, improves service 1.2 MB
1923 Quick Restoration of Wire Service at Broad Street Station 3.5 MB
1936 Railroads Clean Up After Flood Waters 33.3 MB
1911 Railway Signal Association Convention: Committee I: Signaling Practice 3.8 MB
1911 Recent Improvements in Signaling 856.5 KB
1918 Record Snowstorms Paralyze Transportation 424.7 KB
1937 Rehabilitating Flooded Signaling 1.4 MB
1925 Relieving Congestion by Signals 2.5 MB
1947 Remote Control on Baltimore & Ohio 595.8 KB
1936 Remote Control on the Pennsylvania 14.5 MB
1937 Remote Control on the Pennsylvania 5.2 MB
1937 Report of Committee X – Signaling Practice 2.9 MB
1950 Reservations Communication System Installed On the Pennsylvania 3.9 MB
1935 Respacing Automatics on the Pennsylvania 1.8 MB
1924 Results of Train Control Test on Pennsylvania 3.1 MB
1946 Reverse Running on the Pennsylvania 2.8 MB
1937 Rule for Crossing Protection 1.2 MB
1935 Safety of High Speed Trains 5.2 MB
1916 Service Record of Position-Light Signals 580.8 KB
1913 Settled at Last 824.8 KB
1930 Should Signal Clear? 1.2 MB
1928 Signal Aspects for "Head-In" Indication at Passing Track 1.0 MB
1930 Signal Aspects for a Four Block System 2.8 MB
1951 Signal Modernization Program on the RF&P 1.0 MB
1935 Signal Night for New York Railroad Club 1.1 MB
1933 Signal Publicity 666.2 KB
1931 Signaling for Electrified Operation 3.5 MB
1935 Signaling for Higher Train Speeds 3.0 MB
1939 Signaling for the Army-Navy Game 1.0 MB
1911 Signaling on the New York Tunnel Extension of the Pennsylvania 1.0 MB
1933 Signaling on the Pennsylvania's Electrified Line 3.6 MB
1939 Signaling the Pennsylvania to New York World's Fair 4.2 MB
1931 Signaling the Philadelphia Terminal of the Pennsylvania 8.9 MB
1937 Signals in Advance of Switches 1.1 MB
1951 Simple Interlocking Saves Many Train Stops 364.8 KB
1936 Slide Detector Fences 4.3 MB
1936 Slide Detector Signals 12.9 MB
1916 Some Examples of Early Signaling 351.5 KB
1937 Spring Switch at Branch Line Terminus 5.0 MB
1950 Spring Switch Signaling 2.5 MB
1950 Stopping Distance on Grades 3.5 MB
1951 Street and Railroad Crossing Protection Combined 529.9 KB
1961 Survey Tells How Railroads Use Hotbox Detectors 1.8 MB
1950 Temporary Change of Signal Controls 2.2 MB
1936 Testing New Interlocking 3.5 MB
1921 The Development of Position Light Signals 830.7 KB
1926 The Direction of Train Movements by Signal Indication Without Written Train Orders 829.5 KB
1908 The Electro-Pneumatic Signal and Interlocking System at the New Union Station, Washington, DC 4.5 MB
1938 The Outlook for Signaling 1.3 MB
1925 The Position Light Signal 1.7 MB
1911 The Principles of Railway Signaling 3.5 MB
1935 The Rudd-Rhea Signaling Report of the Pennsylvania 9.7 MB
1925 The Train Control Situation 853.0 KB
1926 Train Control Progress in 1925 3.1 MB
1925 Train Operation by Signal Indications – Especially by Cab Signals 1.3 MB
1927 Train Operation Without Written Train Orders 3.3 MB
1954 Train Operations When CTC Fails 2.0 MB
1944 Train Telephone Communication 4.1 MB
1923 Train-Order Signals at Interlockers 3.6 MB
1915 Trenton Electro-Mechanical Interlocking 1.7 MB
1934 Use of Dwarf Calling-On Signals 1.0 MB
1934 Use of Marker Lamps 516.1 KB
1946 W. M. Post retires 932.3 KB
1925 W. M. Post: News of the Month (July 1925) 775.5 KB
1936 What Is the Capacity of a Single-Track Line? 2.0 MB
1929 What Kind of Control for Take-Siding Signals? 512.5 KB
1920 What Scheme of Signaling is Most Desirable? 6.8 MB
1961 What’s the Answer? 1961-04 960.3 KB
1929 Where Should Grade Signals Be Installed? 1.2 MB
Pennsylvania Central 1
1922 The Red Light 624.5 KB
Pennsylvania Station, New York, NY 2
Pennsylvania-New York Central merger 1
1962 News Briefs. 1962-08 685.4 KB
Pennsylvania-Reading Seashore Lines 2
1965 News Briefs. 1965-01 2.0 MB
1950 Passenger Terminal Signals 993.8 KB
Pennsyvania 1
1964 News Briefs. 1964-06 820.5 KB
Pensacola, FL 1
Penticton, British Columbia 1
Peoria & Eastern 1
Peoria & Pekin Union 5
Peoria, IL 4
Peoria, OH 1
1965 News Briefs. 1965-06 1.2 MB
Peosta, IA 1
Pequot, IL 2
Perdido, AL 1
1964 News Briefs. 1964-08 827.3 KB
Pere Marquette 26
1929 Are Automatic Signals on Sidings Justified? 1.6 MB
1944 Canadian Pacific Installs Centralized Traffic Control 4.4 MB
1947 Choice of Interlocking Control Machines 266.5 KB
1935 Circuit for Flashing Light Signals 3.5 MB
1945 CTC Solves Operating Problems On the Pere Marquette 4.3 MB
1930 Directional Approach Lighting 449.8 KB
1946 DT&I Tests Radio 4.3 MB
1933 Economics of Modern Signaling 2.1 MB
1938 Electric Switch Heaters at Rock Island Interlocking 1.8 MB
1937 Gages for Mechanical Locking 2.4 MB
1949 Hold-Out Signals in CTC 1.0 MB
1949 Modern Signaling on a Division 6.6 MB
1915 New Interlockers on the Flint Belt Line 2.2 MB
1923 New Interlockers on the Flint Belt Line 1.6 MB
1928 Pere Marquette Installs Centralized Control Signal System 3.2 MB
1946 Pere Marquette Installs CTC 3.1 MB
1920 Pere Marquette Resort Special in Head-On Collision 354.4 KB
1930 Report of Committee I – Economics of Signaling 2.5 MB
1928 Signal Aspects for "Head-In" Indication at Passing Track 1.0 MB
1934 Signals at Automatic Interlockers 378.1 KB
1945 Teaching the Meaning of Signal Aspects 431.7 KB
1947 Territories Involved in the ICC Signaling Order 399.0 KB
1920 The Use of Signals for Better Train Operation (Part 2 of 2) 7.3 MB
1930 Time-Table Schedules and Signal Indications 1.1 MB
1926 Train Control Progress in 1925 3.1 MB
1946 War-Time Replacement of Interlocking on Pere Marquette 3.4 MB
Pergo, OH 1
1950 CTC on the Wabash 2.6 MB
Perham, MN 3
1961 News Briefs. 1961-06 718.3 KB
1962 News Briefs. 1962-02 1.4 MB
1962 News Briefs. 1962-07 509.0 KB
Perkins, WY 1
permissive signals 3
Perritt, KY 1
1962 News Briefs. 1962-07 509.0 KB
Perry, IA 1
Perry, TN 1
Perryville, MD 3
Pershing, IN 1
Persia, IA 1
personal 24
1949 A. A. Freiberger 827.1 KB
1949 A. H. Rudd obituary 947.2 KB
1937 A. H. Rudd Retires 1.6 MB
1928 Changes on the C&NW 978.4 KB
1937 Changes on the Pennsylvania 1.6 MB
1946 G. H Dryden retires 455.7 KB
1943 Herbert S. Balliet obituary 609.4 KB
1937 J. C. Mock Retires 1.4 MB
1953 News 2.2 MB
1928 Obituary: Frank P. Patenall 627.0 KB
1940 Obituary: Leroy Wyant 1.0 MB
1941 P. M. Gault obituary 1.2 MB
1928 Personal Mention: G. H. Dryden 432.7 KB
1937 Personal Mention: L. B. Porter 1.5 MB
1937 Personal: C&NW 1.3 MB
1940 Personal: Changes on the New York Central 2.2 MB
1950 Personnel changes on the IC 1.4 MB
1953 Stanley E. Noble Retires 703.8 KB
1936 T. George Stiles Rounds Out 60 Years of Signaling 2.5 MB
1931 Thomas A. Edison (obituary) 1.1 MB
1946 W. M. Post retires 932.3 KB
1925 W. M. Post: News of the Month (July 1925) 775.5 KB
1930 W. M. Vandersluis 550.2 KB
1945 William H. Claus (promotion) 425.7 KB
Perth Amboy, NJ 1
1962 News Briefs. 1962-10 457.3 KB
Peru, IL 1
Peru, IN 4
Petersburg, VA 1
phankill unit 1
1937 New Devices- March 1937 18.1 MB
phantom indications 4
Philadelphia & Erie 1
Philadelphia & Reading 4
Philadelphia Rapid Transit 3
Philadelphia Suburban Transportation 1
Philadelphia, PA 21
Philbrook, MN 1
1964 News Briefs. 1964-07 849.5 KB
Phillipsburg, NJ 2
1946 Carryphone on the Pennsylvania 1.5 MB
1963 News Briefs. 1963-01 971.6 KB
Philo, IL 1
Phinney, R. M. 4
Phoebe, VA 1
Phoenixville, PA 1
1962 News Briefs. 1962-02 1.4 MB
photography 2
1956 Photography 1.5 MB
1917 The Use of Photography in Signaling 432.5 KB
Picacho, AZ 1
Piedmont, MT 1
Pierce Jct., TX 1
Pike, Reading, PA 1
Pine Bluff, AR 2
Pine Bluff, MO 1
Pine Jct., IN 5
1961 News Briefs. 1961-07 654.1 KB
1962 News Briefs. 1962-02 1.4 MB
1963 News Briefs. 1963-03 830.1 KB
1963 News Briefs. 1963-04 908.1 KB
1965 News Briefs. 1965-01 2.0 MB
Pine, IN 1
1965 News Briefs. 1965-08 753.7 KB
Pineo, CO 1
Pineville, NC 1
Pinola, IN 1
1965 News Briefs. 1965-08 753.7 KB
Pipas, George 3
1965 Midwest RRs fight the weather 914.3 KB
1953 News 2.2 MB
1964 News Briefs. 1964-06 820.5 KB
Piqua, OH 1
1954 CTC Moves Heavy Trains 4.1 MB
Pitkin Avenue Yard, New York, NY 1
Pittsburg, KS 1
Pittsburgh & Lake Erie 12
Pittsburgh & West Virginia 1
Pittsburgh Jct., OH 1
Pittsburgh, Chartiers & Youghiogheny 1
Pittsburgh, Cincinnati, Chicago & St. Louis 1
Pittsburgh, PA 3
plain bearings 1
Plaines, IL 1
Plainview, IL 4
Plaster Creek, MI 1
Plattsburgh, NY 3
1962 News Briefs. 1962-03 1.1 MB
1962 News Briefs. 1962-06 980.1 KB
1963 News Briefs. 1963-11 1.4 MB
Plattsmouth, NE 1
1955 CTC on single and double track 406.8 KB
plug connector 1
plug coupler 1
plug-in relays 3
Plymouth, MI 2
1958 C&O Has Good Ideas in CTC 2.5 MB
1965 News Briefs. 1965-12 618.4 KB
pneumatic interlocking 1
Pneumatic Railway Signal 1
Pneumatic Signal 1
Pocatello, ID 3
Poe, VA 1
poem 1
Point St. Charles, Quebec 1
Pokegama, WI 1
1961 News Briefs. 1961-10 1.0 MB
polarity-responsive relays 1
1947 Magnetic-Stick Relays 1.0 MB
polarized line circuits 1
1947 Biased Neutral Relays 461.4 KB
polarized track circuits 1
pole line 3
1962 1962 outlook 3.0 MB
1965 Midwest RRs fight the weather 914.3 KB
1954 Quebec, North Shore & Labrador 7.8 MB
pole lines 2
politics 1
Polk, CA 2
1962 Automatic Dispatching 2.1 MB
1962 News Briefs. 1962-11 473.4 KB
Polo, MO 6
Pomona, CA 1
1950 CTC on Sunset Route 3.1 MB
Pomona, IL 1
1948 CTC Big Help to GM&O 1.7 MB
Pompano, FL 1
1964 News Briefs. 1964-12 998.6 KB
Ponca City, OK 1
Pontiac, MI 1
Port Arthur, Ontario 1
Port Authority of Allegheny County 1
Port Jervis, NY 2
1964 News Briefs. 1964-09 899.1 KB
1965 News Briefs. 1965-02 1.9 MB
Port Orange, FL 1
1964 News Briefs. 1964-08 827.3 KB
Port Washington, NY 1
portable radios 1
Portage La Prairie, Manitoba 1
1961 News Briefs. 1961-02 1.4 MB
Portage la Prairie, Manitoba 1
1965 News Briefs. 1965-01 2.0 MB
Portage la Prairie, Manitoba. 1
1963 News Briefs. 1963-05 742.2 KB
Portage, IL 1
Portage, NY 2
Portage, WI 1
1934 Milwaukee to Use Cab Signals 699.1 KB
Porter, IN 7
Porter, L. B. 6
Portland Terminal 2
Portland Union Station, Portland, ME 1
Portland, ME 2
Portland, OR 4
Portola, CA 2
Portsmouth, OH 5
Portuguese East Africa 1
1965 Rhodesia has 1215 miles of CTC 949.2 KB
position color light signal 1
1922 Position Color Light Signal 612.9 KB
position light signals 20
Post, W. M. 4
Potomac Yard, Alexandria, VA 1
power signaling 3
power spring switches 1
power switch machines 1
power switches 8
power transfer relays 2
1935 An Under-Voltage Relay 1.2 MB
1935 Power Transfer Relay 1.3 MB
power-off indications 1
Powhatan, WV 1
Pratt, KS 1
1947 ICC Signal Hearings 179.7 KB
Preble, TX 1
1955 News Briefs. 1955-08 801.6 KB
Prescott, WI 1
presence detectors 1
1964 News Briefs. 1964-05 1.0 MB
Prichard, WV 1
primary batteries 1
primary battery cell 1
1935 New Devices 1.5 MB
Princeton, IN 1
Princeton, WV 1
1963 News Briefs. 1963-03 830.1 KB
private line radio 1
private radio on single frequency 1
Proctor, MN 2
Promenade Street, Providence, RI 1
promotion 2
1949 A. A. Freiberger 827.1 KB
1950 Personal: T. B. Thompson 1.1 MB
Prosser, WA 1
Providence, RI 2
Proviso, IL 2
Provo, UT 2
proximity detector 1
1947 Proximity Detector System 905.9 KB
Prussian Street Railway 1
Pryse, KY 1
1962 News Briefs. 1962-07 509.0 KB
Public Service Railway 1
Public Works Administration 2
publicity 1
1933 Signal Publicity 666.2 KB
Pueblo, CO 2
Pulaski, VA 2
Pullman 1
Punxsutawney, PA 1
1962 News Briefs. 1962-02 1.4 MB
Purcell, OK 1
purchasing 1
1928 Getting What You Specify 866.4 KB
purple 4
Pymatuning, PA 1

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