NCR N-530 Bombe Enigma Decrypting Machine
National Cash Register Company in World War Two
Dayton, OH
1879-1884 National Manufacturing Company
1884-1991 National Cash Register Company
1991-1997 as part of AT&T
1997-2009 NCR in Dayton, OH
2009-Present NCR in Atlanta, Georgia area

This page added 12-29-2022.

This is National Cash Register's signature product for World War Two.  However, because this was a top secret computer that decoded the German's secret Enigma machine, knowledge of this machine was not released to the public by United States Government sources until 1993 when this went on display at the Smithsonian Museum in Washington, DC.  This is the only surviving NCR N-530 Bombe Enigma Decrypting Machine of the 121 built for the U.S. Navy during World War Two.  It is on display at the National Cryptologic Museum at Fort Meade, MD.  Author's photo.

While today's military and NCR historians focus on the N-530 when addressing what the company made during World War Two, it was just a small, yet very important, part of a much larger story of how NCR helped the United States military win World War Two.  Tables 1 and 2 below show the diversity of the products the company made for the war effort.

This NCR webpage will be divided into two pages.  This page will focus on the non N-530 products.  A separate page linked at both the top and bottom of this page will feature an extensive photo gallery of the NCR N-530 at the National Cryptologic Museum. 

An examination of the items listed in Tables 1 and 2 shows that they were mechanical and electro-mechanical in nature.  While the cash registers currently in use are electronic devices, the cash registers prior to World War Two were mechanical adding machines.  National Cash Register was well equipped with punch presses, screw machines, and other machinery to manufacture the fuzes, bombsights, magazines, gun sights, and other similar military equipment required by the U.S. Army and U.S. Navy.

Shown in this and the next photo are some of the many cash registers built by National Cash Register that are on display at the Carillon Historical Park in Dayton, OH.  Author's photo.

Originally formed in 1879 as the National Manufacturing Company to manufacture and market the first mechanical cash register, the company and patents were purchased by the Patterson Brothers of Dayton, OH in 1884.  They renamed the company National Cash Register Company.  Author's photo.

The Class 2000 Payroll Machine was built in various models from 1922 through 1973.  It was the forerunner of many other business machines besides cash registers that the company built.  The 20,143 parts that were hand assembled into the unit are displayed in the display cases below the machine.  The parts display case takes up an entire wall in one of the out buildings at Carillon Historical Park.  Small parts are on the top shelves while larger stamped pieces are shown along the front.  Author's photo. 

This display case has just a few of the many stamped and other manufactured parts that National Cash Register required in order to assemble the Class 2000.  Today, business machines are all electronic.  Not so in the World War Two era.  They were all mechanical or electro-mechanical devices.  This is why National Cash Register was the proper company to make the military items shown below.  Author's photo taken at Carillon Historical Park.

Author's photo taken at Carillon Historical Park.

National Cash Register won the Army-Navy "E" award six times during World War Two. 
The first time was January 28, 1942.
The second time was October 2, 1942.
The fourth time was September 1943.
The last and sixth award was March 12, 1945.

National Cash Register in World War Two:  The company had $86,817,000 in major contracts as noted in Table 1.  Note that the company was contracted by both the Treasury and Navy Departments to make cash registers and office equipment.  These were non-military products that both government agencies needed to keep the bureaucracies running.  The Navy may have needed the cash registers to keep track of sales in its commissaries and BXs. 

There are two Navy contracts labeled as "Classified" totaling $2,400,000.  These two contracts were awarded too late in the war for the construction of the 121 N-530 Bombes the company built, as work started on those early in the war and probably cost more than $2,400,000.  As this was a top secret project, the funding may have been provided in another manner. 

Table 2 lists the many products the company built during World War Two.  It does not give the actual number of components or products produced.  While it gives a "Maximum Production per Month," it is unknown in most cases if that was the true production rate or how long it was produced. 

Fuzes:  National Cash Register produced the M48 P.D. Fuze, 20mm Fuze, M50 Dummy Fuze, M43 A3 Mechanical Time Fuze, M120 Bomb Nose Fuze, M120 Bomb Nose Fuze, and M61 Mechanical Time Fuze during World War Two.  The total value of the company's fuze contracts was $8,116,000.

The M43 fuze provided up to a 30 second delay for 90mm anti-aircraft shells.

This NCR-built M43 fuze is on display at the Veterans Memorial Museum in Germantown, OH, not far from the location of the former NCR complex in Dayton.  Author's photo.

 
The NCR-built M43 fuze was used on the shells that were fired by the 90mm anti-aircraft gun.  Author's photo. 

The Veterans Memorial Museum also has a cut-away example of an NCR-built M120 fuze.  This fuze was used in the 120lb parafrag bombs of the 5th Air Force in the southwest Pacific during World War Two.  Also in the photo is a 20mm shell used by the U.S. Navy in its 20mm Oerlikon anti-aircraft guns.  NCR made the fuzes for the 20mm projectiles.  Author's photo. 

Parafrags being put to good use by a B-25 in the southwest Pacific.  The parachutes allowed aircraft like the B-25 and A-20 to make surprise low level attacks on Japanese airfields.  The combination of the parachute and the timer mechanism in the NCR-built M120 fuze allowed the attacking aircraft to clear the area and escape the bomb blast.  This Imperial Japanese Navy Mitsubishi G4M2a "Betty" long range bomber is about to have a bad day once the NCR-built fuzes time out. 

 Also on display at the Veterans Memorial Museum is this cut-away of an M61 mechanical time fuze for 120mm anti-aircraft projectiles.  Author's photo. 

Author's photo.

This image shows an M61 fuze on 120mm HE M73 anti-aircraft shell.

This is one of the few surviving 120mm M1 anti-aircraft guns of the 550 built by Fisher Body Grand Rapids during World War Two.  It is on display at the USS Alabama in Mobile, AL.  Author's photo. 

Aircraft Bombsights:  National Cash Register produced two of the three bombsights used by the U.S. Army Air Forces in World War Two.  These were the Estoppy D-8 and the Sperry S-1.  While the Norden M9 bombsight is the best known of the World War Two bombsights, it was not necessarily the best American bombsight, in spite of the myth that has been built up over the years since World War Two.  Many officers in the U.S Army Air Forces considered the Sperry S-1 to have been the better bombsight.  However, politics and hype won the day for the Norden M9 and it became the standard bombsight during World War Two.

Estoppy D-8 Bombsight:  Until I began researching the products that National Cash Register manufactured to help win World War Two, I was unaware that there was such a bombsight at the Estoppy D-8 used in World War Two.  I even made a special trip to the National Air and Space Museum Steven F. Udvar-Hazy Center near Chantilly, VA to photograph the one the museum has on display.

Mr. Estoppy began work in 1921 as a civilian engineer at McCook Field, Dayton, OH, after he had immigrated from Switzerland.  The first bomb sight he designed was the D-1.  Previous to Mr. Estoppy's invention of the D-1, the U.S. Army and U.S. Navy used British bombsights.  In 1926 he designed an improved version known as the D-4.  The D-4 was used until Mr. Estoppy invented another improved version designated the D-8.  Production of the D-8 began with other companies in 1938, with National Cash Register commencing production in February 1942 at a cost of $233.05 each.  When production ended in February 1943, the cost had been reduced to $156.00.  From National Cash Register's historical records, full production appears to have been reached in July 1942.  At least 9,339 were built by NCR, which was the primary contractor for this bombsight during World War Two.

This D-1 is on display at the National Museum of the United States Air Force in Riverside, OH.  This is one of 114 that were produced.  Author's photo. 

This D-4 is also on display at the National Museum of the United States Air Force.  Author's photo. 

The Estoppy D-8 has a definite family resemblance to the D-1 and D-8.  Author's photo from the National Air and Space Museum Steven F. Udvar-Hazy Center near Chantilly, VA.

Author's photo. 

The data plate shows the D-8 was built by National Cash Register Company.  Author's photo. 

Author's photo. 

This photo is courtesy of the National Air and Space Museum Steven F. Udvar-Hazy Center.  This photo shows that it is serial number 9339 which indicates the company built at least this amount.  Contract W535 AC23640 is the $2,018,000 contract for Airplane Instruments awarded to National Cash Register in April 1942.

  The D-8 was used on B-24s, B-25s, B-26s, B-34s, and A-20s.  It was not used on the B-17. 

Sperry S-1 Bombsight:

 The Army Air Forces awarded National Cash Register contract number AC24608 for $4,975,000 in July 1942.  While the description in Table 1 is not very descriptive, the contract number matches up with the contract number for this National Cash Register-built S-1 that is on display at the National Museum of the United States Air Force.    Author's photo.  

The Sperry S-1-designed bombsight was built by Sperry, International Business Machines, and National Cash Register.

This S-1 is 5.64 miles from where it was built at the former National Cash Register factory on the south side of Dayton.  Author's photo.

Author's photo.

Looking at the S-1 computing bombsight shows that there was a sighting eye piece for the bombardier to view the target and set up the bombsight.  This was done with the several rotating knobs on the exterior of the device.  Author's photo.

Author's photo.

Author's photo.

Once the cover is removed, it becomes very obvious that the S-1 was a very complicated mechanical computer.  National Cash Register and International Business Machines were both picked by the Army Air Force to build the S-1 due to their previous experience in making similar devices for the civilian market.  Photo  courtesy of  www.glennsmuseum.com.

National Cash Register made four modifications to the S-1 bombsight that were approved by the Army Air Force on August 30, 1943.  The company made the modifications to improve both the manufacturability and performance of the bombsight.  A new style of the clutching arrangement on the azimuth control system was developed.  The company also designed new tangent and degree scales for the device.  The bomb release was fitted with a new switch relay.  The last item, due to its complexity was being investigated by Sperry as a better method.  However, it may not have been implemented due to the unexpected cancellation of the S-1 bombsight program in favor of the better promoted, but not necessarily better, Norden bombsight.  The entire program was terminated at the end of 1943.  The last National Cash Register suggestion under consideration by Sperry was a method to deposit a thin film of magnesium fluoride in a high vacuum to the bombsight's optical surfaces.  This resulted in less reflection in the device and also increased the amount of light transmission in it. 

It is unknown how many S-1 bombsights National Cash Register made.  According to Table 2, it was going to take 12 months to reach initial production, which would have been July 1943.  It was then going to take another five months to ramp up to full production of 158 bombsights per month, which would have been December 1943, when the contract was cancelled.  It probably built a couple of hundred units at most. 

Sperry K-3/K-4 Automatic Computing Gun Sights:  Both gun sights were similar in construction and use.  The K-3 gun sight was used in the upper Sperry B-17 turret which was operated by the fight engineer.  The K-4 was used in the Sperry lower ball turrets of the B-17 and the B-24.  The reason the K-3 was not used in the upper turret of the B-24 is that it was a Martin turret that used a different gun sight. 

The U.S. Army Air Forces awarded National Cash Register four contracts worth $2,594,000 the construction of the Sperry K-3 and K-4 automatic computing gun sights.  The contracts ran from September 1943 until June 1945.

This and the next three images show the complexity and all of the small parts used in the K-4 computing gun sight. 

This image shows the automatic computing gun sight main assembly.

This image shows the computing mechanism assembly.

This image shows the main frame assembly.  NCR was well qualified to manufacture both the Sperry K-3 and K-4 computing gun sights.  All of the small parts used in the gun sights were similar to the parts and construction in the company's cash registers of the era. 

This is a Sperry-designed B-17 top turret that is on display at the National Museum of the United States Air Force.  Author's photo.

Looking up into the turret, the back of the K-3 gun sight can be seen in the upper left of the turret.  Author's photo.

This is the B-17F Memphis Belle which is also on display at the National Museum of the United States Air Force.  Author's photo.

This is the Memphis Belle's Sperry-designed ball turret with a K-4 gun sight installed.  Author's photo.

The K-4 gun sight is in the center of the turret.  Author's photo.

Mark 4 Rocket Motors:  In December 1944 National Cash Register was awarded a $114,436 Navy contract for Mark 4 five-inch High Velocity Aircraft Rocket (HVAR) rocket motors.  The rocket motor assembly did not include a propellant, as that would be installed at an ordnance plant along with the warhead.  

The U.S. Navy used the Mark 4 five-inch HVAR in several aircraft during World War Two, including the TBM shown here.  Other Navy single engine aircraft that used the rockets were the F6F, F4U, and SB2C.  Author's photo.

Author's photo.

Author's photo.

The only Navy twin engine aircraft that used the Mark 4 five-inch HVAR was the Lockheed PV-2 Harpoon.  It could carry four under each wing.  Author's photo. 

37mm M54 High Explosive Shell:
 

The size of the entire 37mm shell can be seen in relation to the World War Two tanker's helmet in the photo.  NCR made a high explosive shell similar to the black painted shell in the photo.  The nose fuze and brass shell casing were made by another company.  All of the components were then assembled into the final product at an ordnance plant.  Author's photo. 

The M5A1 series light tank was mounted with a 37mm main gun which used the M54 high explosive shell.  Author's photo.

20mm Oerlikon Magazines:

This 20mm Oerlikon anti-aircraft gun is on display at the LST-325 Museum in Evansville, IN.  National Cash Register built many of the 60 round magazines that were used on the weapon.  Author's photo.

 There were 137,541 20mm Oerlikons built during World War Two for the U.S. Navy, which was the company's customer for the product.  A total of 1,375,410 magazines would have been required if it is assumed that each weapon required ten magazines.  It is unknown how many magazines the company built.  Author's photo.

  Author's photo.

Due to many changes that National Cash Register made to make the magazines easier to manufacture, the selling price for the magazines in May 1941 was $94.78.  Over the next 29.5 months, the selling price dropped to $35.70 in eight steps.  Author's photo.

While it does not look like a very complicated product from the outside, the 20mm magazines were assembled using a considerable number of components.

Chandler-Evans Carburetors:  Chandler-Evans produced a variety of military aviation components during World War Two.  The National Cash Register Company built three different carburetors as a subcontract for Chandler-Evans during World War Two.

The 58 CPB-4 and 58 CPB-10 carburetors were used on the Wright R-3350-35 engine which were used on the B-29 Superfortress bomber. The 1900 CPB-3 carburetors were used on the Pratt & Whitney 1830-C4 engine which was used on a variety of aircraft during World War Two.  

This image and the one below show a 58 CPB-4 aircraft carburetor.  The other two types of carburetors that NCR built were similar.

M-1 Carbine Parts:  During World War Two the Inland Division of General Motors was the largest manufacturer of the M-1 carbine.  The Inland Division was located on the west side of Dayton not far from the NCR complex.  Inland subcontracted with NCR to make firing pins, piston nuts, hammer spring plungers, operating slide pins, hammers, hammer pins, extractor spring plungers, and magazine catch retaining safety plungers for the weapon. 

This Inland-built M1 Carbine is on display at Fort Macon State Park in North Carolina.  Inland built 2.6 million of these during the Second World War.  Author's photo.

National Cash Register's Factory Complex:  The NCR factory complex was razed, and the land is now part of the University of Dayton.  Below is a Sanborn fire insurance map shows the how big the complex was.  The Google satellite photo below shows the same area today.

The University of Dayton now owns the former NCR property.  All of the former NCR buildings have been razed and replaced by new university buildings and parking lots.  There is no trace of the former NCR complex. 

Sugar Camp:  This was an NCR-owned camp about a mile south of the factory complex with a number of log cabins that were used for off-site sales meetings.  During World War Two, it was the living quarters for the Navy WAVES that were assigned to NCR to assemble components for the NCR N-530 Bombe Enigma Decrypting Machines.

This is Sanborn map shows the layout of the camp on West Schantz Avenue.  This does not show the 60 cabins that were used by 300 WAVES during World War Two.

Sugar Camp was also razed except for two buildings.  The location of the razed buildings has been repurposed with several office buildings. 

One building that was not razed was the gatehouse to Sugar Camp located at the intersection of West Schantz Avenue and Sugar Camp Circle.  Author's photo.

This is the east side of the building.  Author's photo. 

This is the south and west sides of the former gatehouse.  Author's photo.

This is the east and north sides with the attached garage in the background.  Author's photo.

The other building that was not razed was Sugar Camp Cabin #22.  In 2004, it was moved in one piece from its former Sugar Camp home to Carillon Historical Park.  It is now on display less than a mile west of its original location.  Author's photo.

There are several different figures for the number of WAVES at Sugar Camp.  With only 60 cabins, this would mean there were ten WAVES per cabin.  This would have resulted in an overcrowding issue.  The cabins as shown below had two rooms each with two beds per side.  The cabins were set up for four persons.  With 600 WAVES, there was an overcrowding issue.  Some of this was relieved by the fact that the WAVES worked two twelve hour shifts.  Therefore, the WAVES used a hot bunking system where one WAVE slept while the other went to work.  However, there still would have had to have been extra bunks installed in the cabins to accommodate all of the WAVES.  The first winter the WAVES were located at Sugar Camp, there was no heat in the cabins which made for very cold nights trying to sleep.  Author's photo.

 Carillon Historical Park's re-creation of cabin's bedroom does not show the overcrowding that occurred.  Author's photo.

 Author's photo.

 There were two sinks, one shower, and one commode for up to ten WAVES.  Author's photo.

 
There are stories of the WAVES marching back and forth from Sugar Camp to Building 26 where the Bombes were being manufactured.  This Google Satellite view shows the route they marched.  Author's photo.

Far Hills Avenue turns into Main Street north of Schantz Avenue.  The WAVES marched up Main Street and then west on Stewart Street to NCR's Building 26 which was located at the intersection of Stewart Street and South Patterson Blvd.  With two shifts, this happened twice a day.  Dayton police closed the roads when the WAVES were marching.  They did this in all kinds of weather during the year.  Image courtesy of Google Maps.

There was also a mess hall located at Sugar Camp where the WAVES stayed.  In spite of the over crowding in the cabins and the march each day back and forth to work at NCR, the WAVES had it considerably better than the male sailors assigned to NCR.  This is an untold story and not much is known about their involvement.  However, the male sailors had to find their own housing and meals.  The sailors also worked on building components for the Bombes and how to maintain them. 

NCR N-530 Bombe Enigma Decrypting Machine