Military and Government Issued Slide Rules

These slide rules were used in Artillery and Ranging as well as Photography in scaling targets. Aviation and Flight computers, along with Load Adjuster Slide Rules used during WWII are located in the Aerospace Related Gallery as many continued to be used throughout the decades following the war for peaceful missions. Some of these slide rule images are duplicated on their respective manufacturer or country pages.

WWII Submarine
Coning Tower (1943).

British RAF liaison officers at US 8th Air Force Bomber Command (1942)

Senior Sergeant Mikhail Kalashnikov (Kalasnyikov) the inventor of the automatic rifle named after him and designed in 1947

Instructor shows use of E6-B for Navigation Training at Kelley Field, TX (1942)

BBC TV Series The Great War - No25 Artillery Slide Rule

Air Traffic Controller The World At War Sep 1939-April 1944

Communications Post Fort Bragg, By Bernard Hoffman, Life

WWII British WAAF with Weather Slide Rule
More military images may be found on the Historical Photos, People with SRs and Ephemera Gallery

Alex E. S. Green Slide Rules

Designed by necessity and implemented during WWII for B-29 Crews.

REF Green Ship Length Computer
Green Ship Length Computer
Made in USA by Alex. E.S. Green during WWII
For determining the size of Japanese ships, used in conjunction with the B-29 Gun sights. This slide rule was used to find the elusive Japanese battleship Yamato

REF Green Flight Engineers Computer
Green Flight Engineers Computer
Made in USA by Alex. E.S. Green during WWII.
For maximizing the fuel range of B-29 Gun during long over-water missions. Created after the B-29 crew that found the Japanese fleet ran out of gas and had to land in Xian, China

Mo. Mattei Regolo Di Convergenza (Artllery)

Nicola Marras - Italy. Collector, promotes through exibits and educational courses the memory of old calculating devices and ancient navigation systems. Nicola wants young people to understand that the world as we see now, skyscrapers, highways, atomic power, space exploration and the electronic computer, was possible because of simple tools like slide rules. His main event every year is the exibit at Cagliari festivalScienza. His goal is the construction of a permanent museum of calculus. Nicola Marras's Calcolatoria Website (both in Italian and English). Mo. Mattei Regolo Di Convergenza (Artllery)
Made in Italy by Mo. Mattei
Front Scale: 48cm// b [ d , β(1600-3199), β(1600-1) ϒ] b/D \\ 1:25000
Back Slide: [ Sen.ε, Cos.ε, tg.ε, L ]
Back: Instructions (Italian)
Gift of Nicola, Marras.

K&E Short Base Triangulation Rule USArmy

Initials: USBR
K&E Short Base Triangulation Rule US Army
Made in U.S.A. for the US Army - 20" long
Front Scale: Aux Angle "A", Mils [ Vertex Angle "t" mils, base "b" ] Range "R"
Back Scale: [ Vertex Angle "t" mils, base "b" ]
Cursor: 2 hairlines Meters/Yards

REF K&E M4 Graphical Firing Table Slide Rule - 1943
K&E M4 Graphical Firing Table - WWII
Made in U.S.A. by K&E for the US Army, 1943
18.25" long x 2.75" wide.x 0.62" Thick

Notes: The scales are obviously for artillery calculations. There are three slides for ranging the 75mm and 155mm Howitzer with various charges. There is a C and D scale which qualifies the rule as a slide rule. The rule is of the Mannheim type. The base of the rule is mahogany with a lighter wood used for the stators. The surface of the wood is painted and the scales are screened on.
Archive - Clark McCoy Collection

ISRM Howitzer 155mm Graphical Firing Table Slide Rules
Set of 5 - 1972/1974 Vietnam Era

Made in U.S.A. for the US Army, - 18" long x 3.5" wide x 0.25 Thick stock. These are more of a nomograph than a typical slide rule. The specimens were used by a Sgt. Woodard and exposure to the elements in Vietnam have caused the stock to expand and the cursor to shrink making them now unusable. The stress has caused a couple of the riveted plastic cursors to crack and break. A visitor, Paul, to ISRM explains that the hand-written black markings "B 1/230" on some of the rules stand for B(ravo) Battery (Btry), 1st Battalion (Bn), 230th Field Artillery (FA).

Howitzer 155mm Oct1972 GFT Charge 2 & 4

Howitzer 155mm Oct1972 GFT Charge 5 & 6

Howitzer 155mm Oct1972 GFT Charge 7 & 8

Howitzer 155mm Mar1974 GFT Projectile Illumination Charge 2 & 3

Howitzer 155mm Mar1974 GFT Projectile Illuminating Charge 5 & 7

FM 6-40 USMC Manual (27.3Mb) See Page 7-25 for info on GFTs

M114A1 155mm Artillery Crew Vietnam

Overview: To eliminate the difficulties in computing firing data that result from the need to interpolate, the graphical firing table was created. The GFT provides all the information needed to compute firing data in a slide rule form.

Parts: All GFTs are made in two parts.. The rule is a rectangular wooden base on which is printed one or more sets of scales. With a few exceptions, GFTs are printed on both sides. The second part of the GFT is the cursor. This is a transparent plastic square that slides on the rule. Engraved in the plastic of the cursor is a manufacturer's hairline used to determine values from the scales.
Types: The basic GFT format is the same for all weapons. These formats may be divided into three types: low-angle GFTs, high-angle GFTs, and shell illuminating GFTs.
Identification. All GFTs are labeled for identification. The first line of the label on low- and high-angle GFTs indicates the type weapon in bold type; that is, HOW 155mm. Immediately below the weapon type, in smaller print, is the identification of the TFT on which the GFT is based; for example, "155AM2." This is followed by the projectile type and nomenclature, such as "HEM107." The last line of identification of low-angle GFTs tells the charge for which the GFT may be used, such as "CHARGE 4." High-angle GFTs indicate the trajectory "HIGH ANGLE." Shell illuminating GFTs reverse the label with "PROJECTILE ILLUMINATING" on the top and the weapon type on the bottom.

To read more about a 155mm Field Artillery unit in Vietnam see The 1/92nd Field Artillery Association website.

155mm Ordanance

Geo. W. Richardson Ballistic Slide Rule Model of 1917

Geo. W. Richardson Ballistic Slide Rule Model of 1917
Made in USA by Geo. W. Richardson for J. H. Weil & Co.
Front Scale: A (Yards or Meters) [ B (Mils) C ] D (Yards or Meters)
Back Scale: [ B (Mils) C ]
Note: This was not designed for a sliding cursor

C01 USSR Artillery Ranging
USSR Soviet Artillery Ranging
Made in USSR
Front Scale
tg, tg, 10K [Sin1-00, Sin0-10, 10K] Tables

Archive Photo - No longer in collection

Fesenthal (Dalton) Dead Reckoning Computer (c1940-1944) Type E6B U.S. Army Version WWII


Fesenthal (Dalton) Dead Reckoning Computer - Type E6B
Military Version made of Black Anodized Aluminum

Made in USA by G. Fesenthal & Sons, cWWII
Invented by Philip Dalton, LTJG (1903 - 1941) Patent: 2,097,116
Front Scale: Distance Naut Miles, True Air Speed (Time Min, Hrs, Density Altitude, Air Temp )
Back Scale: Wind Correction Angle( True Heading )
Original owner/user (written on sleeve): R.F. Cassidy, Lt. Col. U.S. Army (See bio below)
Gifted by the Ed Millis Collection, Dallas, Texas.
From Eyes of Artillery: The Origins of Modern U.S. Army Aviation in World War II (76MB PDF) by Edgar F. Raines, Jr.
R.F. Cassidy, Lt. Col (Later Major) is mentioned thropuight the text. [pg72] Robert F. Cassidy graduated from West Point in 1939 and was later a 1st Lt. in the 38th Field Artillery Battalion. Cassidy had washed out of primary flight training, but as battalion reconnaissance officer he often flew with the Army Air Forces observer squadrons. He knew every ripple of ground and every firing position at the Leon Springs Reservation. He had, moreover, a genuine flair for fire direction. In the comparative tests of observers before the arrival of the Army Air Forces squadron, Cassidy established the best record. Once airbornc in an L-4 he took an average of two minutes to bring fire on target. In contrast, Army Air Forces observers first had to locate the firing battalion, which sometimes proved difficult. They also did not always find the target. When they did, they required an average of twenty-five minutes to adjust fire on the first target and an additional seven minutes on another. The contrast in performance led the members of Flight B to make Cassidy an honorary member of the Class Before One. [g124] Cassidy headed the new air-observation post concept with the 2nd Division, and took the Field Artillery pilot course and graduated on 6 March 1944 with Pilot Class 17. [pg252] In the Southwest Pacific Area, June 1944-September 1945, General Douglas MacArthur did not place an artillery air officer on his staff, but during the last fifteen months of the war, he acquired two field army headquarters that exercised operational control over ground units. Each of these contained an artillery air officer - Maj. James McCord in Sixth Army and Lt. Col. Robert F. Cassidy in Eighth Army. [pg288] Cassidy as, a Major, later became the Tactics and Gunnery Division and then as a Lt. Col., the executive officer of the Division of Flight Training, a post he held until 6 May 1944, when he became the artillery air officer of U.S. Second Army with headquarters at Memphis, Tennessee. He co-authored athe manual on Technical and Tactical Training of the Field Artillery Sections 1983). Army Ground Forces Light Aviation, redesignated Army Aviation in 1949, owed its existence to the wartime exploits of thousands of air-observation-post pilots, mechanics, and observers. These men had an opportunity to contribute to the war effort because of the actions of ficld grade aviators such as R.F. Cassidy. Col. Cassidy (retired) was interviewed by the author during 1991.

REF Japanese Gunnery Correction Slide Rule
Japanese Gunnery Correction Slide Rule
Made in Japan - 1936 pre WWII
Front Scale
tg, tg, 10K [Sin1-00, Sin0-10, 10K] Tables

Archive - Image from Duke University, Gessler Collection
A combination slide-rule/nomograph forcalculating ballistics corrections for temperature, barometric pressure, vertical and horizontal wind and muzzle velocities. Probably used in land-based Army operations in China. Weighing 16 pounds it measures 30x38x2.5 cm. It has a thick wooden base, thick bronze or copper dovetail slides (with matching serial numbers 26), and white brass faceplates. Three sliding scales are side-by-side, with a fourth sliding scale inserted in the center slide.

Hemmi "Sun" Type 98 Maneuvering Slide Rule c1938


Japanese Battleship YAMATO

Another of these slide rules was discovered in a bunker, located under a mountain behind the old Taura pyrotechnic factory, which manufactered torpedos during WWII, and stored them within. The buildings are currently part of the Maritime Self-Defense Force Yokosuka Zosamu depot and Akebono Machinery Co., Ltd. The bunker with its network of tunnels is not open to the public. See Yakumo's blog (in Japanese). Google will do a decent translation.
Hemmi "Sun" Type 98 Maneuvering Slide Rule
Made in Japan by "SUN"
Background: "Type 98" denotes that it was created in AD1938 (Koki or Jimmu Era 2598), which is 1938 in western calendars. The type 98 Movement rule, is a polar coordinate measuring system and was designed to calculate tracking and range data between two moving ships (or objects) to, possibly, provide input to the Type 98 Hoiban and Shagekiban Low Angle Fire Control computer which was specially designed for the Yamato class of battleships (the Yamato and Murushi). It could also have been used as the primary calculator for the smaller guns that were not connected the the electromechanical computers on the main battery of guns. This slide rule could also have been used for Ship-to-Shore or Shore-to-Ship bombardement as well. Another feature of this slide rule is that the Maneuvering Board, with its rotating dial on the slide, can be used to determine course corrections and wind drift. Handy if the battleship Yamato or an aircraft carrier, is to launch an aircraft, it will calculate the best heading into the wind. Submarines, would also use a similar device to calculate intercept vectors. The design of this slide rule mimics the maneuvering board/tables of the Allies, designed in 1920, and is still in use today. The center of the dial is 'My' or 'Own' ship.
Scales and markings translated by Jiro Higuchi
Front Scale
Relative Coarse Angle // Speed of My Ship [ Speed of Standard Ship, Distance (Logarithmic Scale) nautical mile/Meters, ] Velocity \\ Velocity Ratio
Back Slide: Time Board, Distance by reading Hour/Nautical Mile or Minutes/Meters
Well: Velocity Ratio =>1, Angle of course alteration, Velocity Ratio =<1
Case: Naugahyde with military division "Air Armament 9/90"
Gift of Phillip Rodley, Upper Hutt, New Zealand
Phillip Rodley

REF V2 Rocket Ballistic Ranging Slide Rule

REF V2 Rocket at Pennemünde

Note from ISRM curator, Mike Konshak, who is certified to build and fly high powered rockets: On the V-2 Rocket slide rule, all the scales are a variation of High vertical climb (maximum altitude), maximum range, burn closing speed. The V2 ballistic missile would shut off its motor at some point in its flight (burn closing speed) which was the maximum velocity at that point, which was determined by it s inertial guidance system. This would vary based on the desired range. At that point it went from the boost phase to the coast phase and begin slowing down due to parasitic drag and fell (still very fast) to its intended target. It was was not very accurate as it only went in the compass direction it was told to go. Full cutoff determined the range. This slide rule was not very different from other artillery calculators.

V2 Rocket Ballistic Ranging Slide Rule - c1942
Made in Germany - Heeresversuchsanstalt Peenemünde (Army Research Center Peenemünde)
Scales: Interpretation provided by Dr. Klaus Schug, as follows:
From distance from Pennemünde to London is about 950 KM or almost 600 miles. This would be the Maximale Reichweite = 950 KM. Its maximum vertical height was between 50 to 60 miles (80 to 95 KM) for long-range targets. This would be the senkrechte Steighöhe = say 90 KM.
I. zur senkr Steighohe - Vertical height in meters. Using 9.0 or 90,000 meters = 90 KM as the heigth for reaching London from Peenemünde to London
II. zur Maximale Reichweite - Using 90 KM (9x10*4) on scale I , then scale II would read about 7000 kg/m*2 = Ballistische belastung = 5163.2 lb.ft of load or stress on the rocket
III. senkrechte Steighohe - Looks like this scale was only for very short distances up to 80 KM using the top of scale IV as the distance desired and then looking at III to see how high up the rocket had to go to reach the distances on the top of scale IV.
IV. Maximale Reichweite - using this scale with III gave the maximum distance for the height in scale III.
V. zur max. Reichw. - Using the bottom of the scale, scale V, to hit longer distances, say 950 KM to hit London, yields on scale V.
VI. Brennschlussgeschwindigkeit - Yields a end of burn velocity 900 m/sec to reach London or a target at 950 KM.
Archive - Image from Pennemünde Museum

ISRM U.S. Military 76mm Howitzer Artillery Set
U.S. Military 76mm Howitzer Artillery 2 SR set
Made in USA - 1952 (Korean Era)
Scales: Range, Elevation, Drift, etc

S552 Soviet-LFAI Artillery
Soviet-LFAI Artillery
Made in USSR
Front Scale:
1:50000M, 1:25000M // β, N² [Sin, S&T, Tg, N ] NQ+1, L
Back Scale: [ Sin, S&T, Tg, N ]
Back: Position and spotter formulae
Multiple hairlined Cursor

ISRM LFAI Soviet Military Dual Circular
Soviet Military Dual Circular - 1957
Made in USSR by LFAI, Leningrad
Left Scale: 10000 meter (Sin)
Right Scale: 10000 meter (Tg)
Back: Position and spotter formulae
Actual application unknown at this time

S495 Lawrence 505_U.S. Navy
Lawrence 505_U.S. Navy
Made in USA - Peru, Ind. (Lawrence)
Painted wood body
Front Scale
A [ B, CI, C ] D, K
Back Slider
[ S, L, T ] Back: Conversion Chart

REF Lawrence - DeYOE Slide Rule, U.S. Army for Artllery Ranging
Lawrence - DeYOE Slide Rule, U.S. Army for Artllery Ranging
Made in USA by Lawrence
Front Scale
E-Mils [ R or H, R or dH ] UOE
Back: Not Shown
Archive - Scan donated by David Rance collection. Sassenheim, The Netherlands

ISRM American Blueprint Military Rule
American Blueprint Military Rule
Made in USA - by K&E for American Blueprint (Military contractor)
Front Scale
Opposite Angle Deg, Mils [Apex Angle Mils, Deg, CI,C] D,A
Back slider: [Tan, Sin-Tan, Tan ]
Back: Geometry formulae
TM 6-240 Manual 3.35MB Pdf
Field Artillery Military Slide Rule

ISRM Pickett Model 14 US Military
Pickett Model 14 US Military
Made in USA
Front Scale
LL1+/-, LL2+/-, A [ B, T, ST, S, K,  C ] D, LL3+/-, LL4+/-
Back Scale
Opposite angle Degrees, Mils [ Apex angle, Tan, Sin-Tan, Sin, Base C ], Distance D, A

US Navy Calculator For Vertical Aerial Photography, MIL-C-19729

US Navy Calculator For Vertical Aerial Photography, MIL-C-19729
Made in USA by Fesenthal Instrument Co., Mfg Part Number FNA-82B U.S.
Front Scale
Air Speed, %Overlap (Minutes, Hours, Density Altitude, Air Temp., Pressure Altitude
Back scale
Feet On Ground, Scale,Focal Length, Exposure, Ground Speed, etc(Feet on Negative, Altitude)
Gift of Aron J. Davidson
Aron writes: "I was an engineer for the Navy (Civil Service)for almost twenty years, and then another twenty five or so as a contractor. I spent a big chunk of my time working on R&D of tactical airborne photographic reconnaissance systems. There really isn't much of a story to go with this slide rule. It was primarily for operational use in mission planning, which I rarely got involved in, but someplace along the line it wound up in my desk drawer; and I'm a bit of a packrat." Aron gave his granddaughter a Pickett slide Rule that he used.

Union Instruments MIL-C-4318-B Type A-1

Union Instruments MIL-C-4318-B Type A-1
Made in USA by Pickett
Front Scale
L, A, DF [ CF, CIF, T, S, C ] D, DI, K
Back scale
Ground Size Meters, Feet, Ground Speed, [Image size, Cycling Time, Focal Length ] Altitude
USAF Manual 8.69Mb

P232 Pickett N700-T USAF Aerial Photo Type A-2
Pickett N700-T USAF Aerial Photo Type A-2
Made in USA for the USAF
Front Scale
L, A DF [ CF, CI, T, S, C ] D, DI, K
Back Scale
Ground Size Meters, Feet, Ground Speed, [Image size, Cycling Time, Focal Length] Altitude
USAF Manual 8.69Mb

Pickett N520-T USAF Aerial Photo
MIL-C-4318-B Type A-1


Pickett N520-T USAF Aerial Photo - MIL-C-4318-B Type A-1
Made in USA by Pickett. Aluminum stock.
Front Scale
L, A, DF [ CF, CIF, T, S, C ] D, DI, K
Back scale
Ground Size Meters, Feet, Ground Speed, [Image size, Cycling Time, Focal Length ] Altitude
Original owner used this in Rotorau, New Zealand, assumed to be part of the Royal New Zealand Air Force.
Gift of Phillip Rodley, Upper Hutt, New Zealand.
USAF Manual 8.69Mb

ISRM USAF Type A-1 Aerial Photo
USAF Type A-1 Aerial Photo - c1950
Made in USA for Astrodyne by Precision Scale Co. (founded by Art Eckel)
Front Scale
L, A, DF [ CF, CIF, T, S, C ] D, DI, K
Back scale
Ground Size, Ground Speed, [Image size, Cycling Time, Focal Length ] Altitude
USAF Manual 8.69Mb

REF Military Attack Computer
Military Attack Computer
Made in USA
Front Scale
Air Speed, Lead angle, Time, Distance, etc.
Archive - Not in collection

Copyright © 2003-2017 International Slide Rule Museum