U. S. Army 1
U. S. Congress 1
Union 1
1949 Insulation of Rails 874.8 KB
Union Avenue, Chicago, IL 2
Union Jct. 1
Union of Soviet Socialist Republics 1
Union Pacific 39
1936 34 Train Stops Eliminated Daily by an Interlocking 10.4 MB
1949 625 Miles of CTC in one Stretch 7.9 MB
1933 A New Deal on Train Control 639.0 KB
1943 A Review of 1942 2.9 MB
1934 An Automatic Wheel Counter on the Union Pacific 1.2 MB
1949 An Unusual Automatic Plant 4.5 MB
1949 Applications to ICC 1949-11 926.1 KB
1928 Are Call-On Signals Safe? 1.2 MB
1937 Broken Rails 1.1 MB
1935 Cab Signals and ATC on UP Streamliner 2.1 MB
1933 Call-On Signals (editorial) 1.0 MB
1937 Color Light Signals Replace Semaphores on Union Pacific 4.2 MB
1956 Conelrad – A Civil Defense Measure … How Some Railroads are Participating 4.1 MB
1927 Control of Stop Indication in Approach-Lighted Territory 972.5 KB
1936 Demands for Modern Signaling 12.1 MB
1935 FPL Adjustment on Spring Switches 1.3 MB
1939 Mission Tower Interlocking at Los Angeles 9.2 MB
1939 New Interlocking at Los Angeles 9.6 MB
1956 New Three-Track Interchange Includes Interlocking and Talk-Backs 8.9 MB
1930 New Type Rail Crossing Uses Turntable Principle 964.5 KB
1941 Non-Stop Permissive Signals 1.4 MB
1956 Photography 1.5 MB
1935 Pole Lines for Automatic Signaling 1.6 MB
1931 Preparation of Signal Circuit Plans 2.0 MB
1944 Railroad Applications of Electronics 1.9 MB
1911 Railway Signal Association Convention: Committee I: Signaling Practice 3.8 MB
1937 Remote Control Switch Expedites Trains at a Junction on the Union Pacific 5.1 MB
1935 Safety of High Speed Trains 5.2 MB
1928 Signal and Train Control Hearing Ends 2.0 MB
1935 Signaling in Dust Storms 2.3 MB
1935 The Railways' Answer to the Demand for Speed 2.8 MB
1931 Three Large Interlockings Installed by Union Pacific at Omaha 6.2 MB
1944 Track Circuits on Passing Tracks in CTC Territory 941.8 KB
1926 Train Control Progress in 1925 3.1 MB
1943 Union Pacific Installs CTC on 175 Miles of Single Track 13.2 MB
1956 Union Pacific Installs Protection For Motor Cars at Tunnels 3.2 MB
1937 Unusual Signal Trouble 1.2 MB
1939 Unusual Signal Trouble 835.4 KB
1920 What Scheme of Signaling is Most Desirable? 6.8 MB
Union Route 1
Union Route interlocking 5
Union Station, Washington, DC 1
Union Switch & Signal 123
1929 "Union" Clock-Work Time Release 611.8 KB
1929 "Union" Thermal Relay 1.0 MB
1936 34 Train Stops Eliminated Daily by an Interlocking 10.4 MB
1921 A New Idea in Traffic Locking On the C&O 1.7 MB
1929 A Time-Element Relay 572.7 KB
1936 Alining Signals on Curves 3.7 MB
1939 An Improved Flasher Relay 1.8 MB
1935 An Under-Voltage Relay 1.2 MB
1934 Application of the Retained-Neutral Relay 842.8 KB
1944 Automatic Signaling, Train Stop, and Route Interlocking Installed in the Chicago Subways 8.6 MB
1941 Belt Railway of Chicago Installs Interlocking 12.3 MB
1928 C&O Signaling and Train Control Facilitate Operation 4.1 MB
1935 Cab Signals and ATC on UP Streamliner 2.1 MB
1944 Canadian Pacific Installs Automatic Block Signaling 6.8 MB
1946 Carryphone on the Pennsylvania 1.5 MB
1932 Centralized Traffic Control 3.1 MB
1935 Centralized Traffic Control Installed on the Pittsburgh & Lake Erie 12.9 MB
1943 Centralized Traffic Control on the Milwaukee 2.8 MB
1943 Centralized Traffic Control Speeds War Traffic on 80.5-Mile Section of the Southern Pacific 10.3 MB
1952 Chicago's Newest Subway Has Automatic Block Signaling and Train Stop 1.1 MB
1928 Circuit Polarity at Relay Contacts 526.2 KB
1941 Code-Following Polar Track Circuit Relay 1.4 MB
1935 Coded Track Circuit Control 1.5 MB
1944 Coded Track Circuits for CTC and Cab Signaling 4.0 MB
1937 Color Light Signals Replace Semaphores on Union Pacific 4.2 MB
1950 Continuity of Train Communication 2.6 MB
1939 CTC and Automatic Signals on the Rock Island 6.6 MB
1950 CTC Installed on 128 Miles of NKP 12.1 MB
1946 CTC on 107 Miles of Single Track on the Louisville & Nashville 5.2 MB
1950 CTC on Sunset Route 3.1 MB
1943 CTC on the Bessemer & Lake Erie 8.7 MB
1940 CTC on the New York, Ontario & Western 8.2 MB
1952 CTC Pays Its Way on B&O 733.2 KB
1944 CTC Speeds Ore Traffic On the DM&IR 4.6 MB
1952 Double-Track CTC on Illinois Central 759.7 KB
1920 East Somerville Electro-Pneumatic Plant 754.4 KB
1943 Electric Interlocking Installed On IC 12.8 MB
1925 Eliminating the Written Train Order 2.8 MB
1937 Ends of Double Track Controlled by CTC 12.4 MB
1956 How to Control Signals Safely Where Lightweight Trains are Operated 8.4 MB
1925 IC Markham contracts: News of the Month (June 1925) 579.3 KB
1925 Illinois Central ATS contract: News of the Month (July 1925) 700.0 KB
1937 Illinois Central Petitions to Remove Train Control 1.6 MB
1936 Improved Position Light Signal 4.3 MB
1939 Improved Searchlight Signal 3.3 MB
1926 Improved Type of Circuit Controller 970.7 KB
1944 Inductive Train Communication 3.9 MB
1925 Inter-Control of Electric and Mechanical Functions at Interlocking Plants 1.6 MB
1936 Interlocking and Remote Control on Erie 18.9 MB
1935 Interlocking on Southern Pacific Suisun Bay Bridge 4.6 MB
1940 Interlocking on the Hudson & Manhattan 6.8 MB
1952 Interlockings Modernized at Three Railroad Crossings 974.7 KB
1937 J. C. Mock Retires 1.4 MB
1943 Junction and Crossing Included in Centralized Traffic Control On the Missouri Pacific 4.7 MB
1920 Largest Saxby & Farmer Machine in the United States 1.6 MB
1917 Light Signals On CM&StP 781.9 KB
1936 Light-out Relay for AC or DC 2.3 MB
1941 Loss of Shunt 912.3 KB
1950 Microwaves on Railroads 1.3 MB
1939 Mission Tower Interlocking at Los Angeles 9.2 MB
1933 Modern Signaling in Soviet Russia 2.9 MB
1944 N&W Installs CTC on Shenandoah Valley Line 10.2 MB
1944 New All-Relay Interlocking at Providence, RI on the New Haven 5.8 MB
1940 New Automatic Block Signaling on the Milwaukee 6.3 MB
1940 New Code Transmitter 2.1 MB
1937 New Devices- March 1937 18.1 MB
1936 New Electro-Pneumatic Plant On Pennsylvania at Newark 23.9 MB
1956 New Haven Consolidates Control of Nine Interlocking Layouts 8.3 MB
1939 New Interlocking at Los Angeles 9.6 MB
1921 New Interlocking on the Boston Elevated 3.3 MB
1921 New Interlockings at Jacksonville Terminal 3.4 MB
1928 New Line of DN Relays 816.5 KB
1928 New Long-Range Search-Light Signal 1.1 MB
1940 New Signaling on the Wabash 8.1 MB
1956 New Three-Track Interchange Includes Interlocking and Talk-Backs 8.9 MB
1943 New York, Chicago & St. Louis Installs Centralized Traffic Control on Busy Sections of Single Track 7.9 MB
1943 Norfolk & Western Installs CTC on 14 Miles of Single Track 4.4 MB
1941 P4 Code-Following Relay 1.1 MB
1937 Pennsylvania CTC Installation 7.0 MB
1940 Pennsylvania Installs Centralized Traffic Control On 69 Miles of Line 13.1 MB
1944 Pennsylvania Installs CTC On 53 Miles of Busy Single Track 8.5 MB
1952 Pennsylvania Railroad Installs Large Modern Interlocking at Passenger Station in Philadelphia 1.6 MB
1939 Plug Connector for "H-2" Searchlight Signals 1.1 MB
1940 Plug Couplers for Relays and Signals 1.3 MB
1936 Power-Transfer Relay for Crossing Signals 3.5 MB
1925 PRR construction (Lima, et al): News of the Month (July 1925) 675.8 KB
1936 Reconstruction of Interlocking at the Dallas Union Terminal 14.8 MB
1956 Remote Control Converted to CTC 6.6 MB
1937 Remote Control on the Pennsylvania 5.2 MB
1935 Remote Control on the Seaboard 5.4 MB
1950 Retained-Neutral Neutral Relay 3.4 MB
1937 Rock Island Installs Automatic Blocks 10.1 MB
1944 Rock Island Installs Cab Signaling and Centralized Traffic Control 10.0 MB
1950 Route Type Interlocking on New York Subway 8.7 MB
1944 Santa Fe Installs CTC on 115.6 Miles Los Angeles to San Diego 7.2 MB
1937 Shunt Sensitivity and Broken Rail Protection 4.3 MB
1937 Signal Construction on the Wabash 12.2 MB
1944 Signaling Modernized On the Pittsburgh & Lake Erie 4.7 MB
1937 Signaling on the Wabash 3.7 MB
1949 Signaling Saves Time on Frisco 4.8 MB
1956 Small Flat Top Console for Controls And Separate Diagram for Indications 5.3 MB
1952 Speed Control Installed on the Long Island 1.3 MB
1950 SS Protection 2.1 MB
1944 St. Louis Southwestern Installs Centralized Traffic Control 6.9 MB
1944 St. Louis-San Francisco Installs Centralized Traffic Control 8.3 MB
1910 The Multiple Unit Electric Interlocking Machine 1.5 MB
1911 The Staff System on the Southern Pacific 4.0 MB
1913 The Union’s Signaling Exhibition Room 1.5 MB
1939 Track Relay Release Time 1.8 MB
1937 Track Shunting Problems 2.5 MB
1926 Train Control Progress in 1925 3.1 MB
1909 Train staff installation on the NYNH&H 1.0 MB
1944 Train Telephone Communication 4.1 MB
1943 Union Pacific Installs CTC on 175 Miles of Single Track 13.2 MB
1932 Union Retained-Neutral Polarized Relay 471.0 KB
1909 Union Switch & Signal’s Inspection Trip 1.5 MB
1928 Union Type HC5 Flasher with Vertical "Stop" Sign 495.9 KB
1929 US&S float 512.3 KB
1946 War-Time Replacement of Interlocking on Pere Marquette 3.4 MB
1929 What Is the Future of Train Control? 1.8 MB
1942 Why Coded Track Circuits Can Be Longer 864.8 KB
1936 Yard Entrance in Montreal Remotely Controlled 8.2 MB
1930 Yard Track Indicator and Control Stand 632.6 KB
United States Army 1
unusual signals 1
1950 Unusual Signals 1.1 MB
UP M-10001 1
upper quadrant semaphore 1
1928 Obituary: Frank P. Patenall 627.0 KB
Upper Sandusky, OH 1
1937 New Automatics on the C&O 5.0 MB
Utica, NY 2
Uxbridge, England 1

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