Know Your Enemy

Soviet delivery systems and chemical agents wheel chart. Probably produced by one of the NATO countries.

I do not have in my collection.

Tulloch Computer for Chemical Agents

This is the Tulloch Computer Mark 6 for the identification/use of chemical warfare agents. It is 4 inches/105mm in diameter and made of card.

It is a curious thing. I have yet to find any online reference to the Tulloch Computer and yet this is apparently version 6. What happened to versions 1 to 5? Who or what was Tulloch?

It is not as professionally made as some produced during the Cold War by some NATO countries and neither is it an amateur hand written production. It would have been cheap to produce which might suggest it was produced in large numbers. Its size suggests it was meant to be used in the field rather than at a desk.

I think somebody has put a plastic coating over parts of it. Presumably to protect it during use.

On its back there is some advice on the use of NAPS tablets and Combo Pens to treat the contaminated.

Some of the gases [e.g. mustard gas] were used in WW1. Sarin was available in WW2.

I suspect [on such little evidence] that it was produced in Britain for use by the army in WW2. However, it could have been made later for use in a conflict with a chemically unsophisticated opponent.

Please leave a comment if you have anything to add.

Cold War Water Contamination Calculator No. 1

This calculator was produced by BRL Limited for the British government. It was designed by the Atomic Energy Research Establishment at Hartwell in England for issue to civil defence organisations.

The calculator is five inches [130mm] in diameter and consists of three plastic disks and a cursor. The one shown in the photographs was produced in 1963. I do not have a copy in my collection.

Nuclear Bomb Effects Computer sales brochure

Note the price of $1.75 for one computer. Peter Sellers was seen using one of these in the Dr Strangelove film. I think they were also given away to people attending some of the early performances of the film.

Chemical Agent Calculator

This calculator surfaced in Greece but is probably of US origin. No author information is shown but its reference number is 6LS-2820. Its purpose is to calculate the amount of a chemical agent required to saturate a target using a number of different delivery systems [e.g. 4.2″ mortar, howitser, rocket or 100 gallon airborne spray tank].

The back of the calculator refers to agent GB. That is the nerve gas Sarin.

The directions also refer to agent HD. This is mustard gas. Agent VX is the VX nerve gas. Under the UK’s Rainbow Code system VX had the code name “Purple Possum”.

The disk refers to the US Honest John and Sergeant missiles as possible delivery vehicles. Honest John was first deployed in 1953 [and remained in the NATO arsenal until 1985] but the M139 chemical weapon warhead was not available for the Honest John until the 1960s.

M139 warhead containing Sarin bomblets

The Sargeant missile was deployed in Europe from 1963.  A chemical weapon warhead option was considered but the development project was cancelled in 1970.

The calculator consists of three disks. The largest is made of card and is just under 5″ [125mm] in diameter. It is fairly crudely made compared to the very high quality Cold War calculators later produced by Perrygraf.

Please leave a comment if you have any more information on this calculator.

Cold War Calculator for Radiation Contaminated Food

A rare British Cold War calculator. Presumably intended for use  by civil defence after a nuclear attack.

The DNA Multi-sigma Damage Prediction Rule MSIG – 1 Cold War slide rule

The MSIG – 1  Multi-sigma slide rule was produced by the US Defense Nuclear Agency to assist military planners in calculating the probability of damage resulting from a nuclear detonation.

The rule is 8″ [205 mm] in diameter and  produced by Perrygraf. It was designed by the DNA and is dated April 1987. This rule is very collectable but the hardest to find of all the DNA slide rules. The one shown was never issued and is in mint condition.

The MSIG -1 was the last slide rule to be produced by the DNA. After that they only supplied software for use on desktop and hand held machines. A list of the slide rule and software can be found in this post.

The complete package as issued consisted of a binder, hard cover, documentation, slide rule and two floppy disks.

The Defense Nuclear Agency’s Cold War calculators

The Defense Nuclear Agency was an offspring of the Manhattan Project and is now part of the Defense Threat Reduction Agency. In its various guises it had many responsibilities connected with America’s nuclear weapons programmes.

In the 1980s and 1990s it produced a series of calculators to help the military plan its nuclear attacks on targets in the USSR and other countries. The US had a list of target Vulnerability Numbers [see this post].  Planners could use these numbers and the DNA calculators to decide whether  a bomber, a submarine launched missile or a ground launched missile be used against a target [they had different levels of accuracy] to achieve a specified level of damage and probability of success.

The first calculators were circular slide rules, designed by the DNA and produced by Perrygraf. These rules are now both very collectable and very rare. A list of these rules is below.

This blog has posts on all these. The list is incomplete because the DNA produced a Damage Prediction Rule VN – 1 in 1982 [see this post].

As soon as a introduction of the IBM PC created a technical standard for personal computers the DNA began producing nuclear targeting software programs.  Some of the DNA’ss programs duplicated the functionality of the above slides rules. The Multi-sigma Damage Prediction Rule was produced as both a physical slide rule and as  software programs for hand held and desktop machines.  Programs for a long list of other targeting functions were added to the DNA catalogue.

The Nuclear Bomb Effects Computer Versions 1, 2 & 3

There were three versions of the Nuclear Bomb Effects Computer.  The first was designed by EG&G.

“EG&G, formally known as Edgerton, Münchhausen, and Grier, Inc., was a United States national defense contractor and provider of management and technical services. The company was involved in contracting services to the United States government during World War II and conducted weapons research and development after the war.” Wikipedia.

The calculator was based on test data published in the first edition of the ‘The Effects of Nuclear Weapons’.  The calculator is made of plastic and is 4″ in diameter. A complete set consists of the calculator, a red and white sleeve and an instruction pamphlet.  This cold war calculator is very rare.

Nuclear Bomb Effects Computer V1

Nuclear Bomb Effects Computer V2

A revised version of the calculator was designed by the Lovelace Foundation. See this post for more information. Like V1 this calculator is very rare.

Nuclear Bomb Effects Computer V3

The third version of the calculator was also designed by the Lovelace Foundation. Its design is much improved over the earlier versions and is based on a revised test data set which was published in the second edition of the ‘The Effects of Nuclear Weapons’. The calculator is 5″ in diameter and is made of plastic. This version is not rare. Copies of the calculator were on public sale for $1 along with the revised edition of the ‘The Effects of Nuclear Weapons’ for $3.  The calculator was used as a prop in the Dr Strangelove film and copies were given away to promote the film. See this post for more information.

Defense Nuclear Agency Weapon Effects Rule 1983

Cold War Weapon Effects Rule designed by Horizons Technology for the US Defense Nuclear Agency and manufactured by Perrygraf.

Defense Nuclear Agency Damage Prediction Rule 1986

This Cold War Damage Prediction calculator [version 2] was commissioned by the Defense Nuclear Agency and designed by Horizons Technology Inc. of San Diego in 1986. The 8″ diameter rule is made of plastic and was produced by Perrygraf. It consists of seven desks, a base disk and three tabbed disks [for HOB, VN adjustment and yield] on either side.

See an earlier post for the 1982 version of this rule. The 1982 version of the rule colour coded the sides for P and Q type targets. This rule prints the target type on the rule.  The rule has the same purpose as the Damage Probability Computer produced by RAND [see this post] but is far more sophisticated.

For more posts about Cold War calculators click on the Cold War Calculators category on the right.

The rule uses the vulnerability number system to calculate the probability of destroying a target given variables such as warhead yield, CEP  [circular error of probability, accuracy of delivery vehicle], HOB [height of burst], WR [weapons radius] and the target’s vulnerability number  [e.g. 18P5].

Defense Nuclear Agency Damage Prediction Rule 1982

This Cold War Damage Prediction calculator  [VN 1] was commissioned by the Defense Nuclear Agency and designed by Horizons Technology Inc. of San Diego in 1982. The 8″ diameter rule is made of plastic and was produced by Perrygraf.

The purpose of the rule was to allow planners to calculate the probability of destroying an enemy point or area target by attacking it with a nuclear weapon.

The rule has the same purpose as the Damage Probability Computer produced by RAND [see this post]. The DNA rule is more sophisticated and has the following additional features.

1.  It can be used for attacks on area targets [towns and cities] and not just point targets.

2.  It allows aim point offset.

3.  It allows conversion from feet to meters [useful when used in a NATO context because at the time some NATO members were using the metric system and some imperial units].

The rule’s documentation makes clear that calculations are made using the Vulnerability Number system [see this post]. The blue side of the rule was used for targets assigned a P vulnerability number and the green side for those with a QVN.

When used in planning attacks on a area target the RT is the target radius which includes 95% of the target elements. HOB is height of burst.

Defense Nuclear Agency Cratering Prediction Rule

Defense Nuclear Agency Cratering Prediction calculator

 

This Cratering Prediction Rule [CRG – 1] was designed for the Defense Nuclear Agency by Horizons Technology Inc. of San Diego in 1984. The 8″ diameter rule is made of plastic and was produced by Perrygraf.  The rule was used to calculate what craters would be produced by nuclear weapons.

The inputs to the rule are weapon yield, height or depth of burst and target geology. One side of the rule was used to estimate crater radius, volume and depth [and debris thickness] in dry soil. The other side was used for wet soil, soft dry rock, soft wet rock and hard rock.  The weapon yield could be in the range 1 kiloton to 100 megaton.

I assume the rule was used to calculate the results of using nuclear weapons on  rail and road transport bottlenecks and airfields. For such targets cratering could have a significantly disruptive effect.

During the Cold War potential targets were given vulnerability numbers [see this post]. Most targets were given QVN or PVN numbers  depending on whether the target should be best attacked using overpressure [crushing  pressure] or  dynamic pressure [horizontal pressure].  PVN targets are best destroyed by crushing, QVN targets are destroyed by being knocked over. Both RAND and the DNA produced rules to assist in planning attacks on such targets and these are covered in separate posts..

It was hard to cause difficult to repair damage to targets such as rail track, roads or runways with either overpressure or dynamic pressure. Cratering was the most effective form of attack. Such targets were given ZVN numbers. For example, roadbed and rail tracks were given a VN of 45Z0. The Cratering Prediction Rule could be used to plan attacks on such targets. A cratering prediction computer program was also available.

By 1984 desktop computers and hand held programmable calculators were available  and a newsletter that was distributed with the rule mentioned that the DNA was currently supporting the HP-41/HP-71, IBM PC, IBM PC/XT and Zenith Z-100. The IBM PC had been introduced in 1981 and was rapidly becoming the standard for personal computing. Before then each computer manufacturer has their own hardware, operating system and storage. There was a great deal of incompatibility and it was hard for software developers to know what system to support.

The newsletter mentioned that the DNA had supported the Texas Instruments TI-59 programmable calculator. but that device was no longer produced. The DNA had produced programs on Fallout, X-Ray Effects and Aircraft Vulnerability for the TI-59.  At the time air to air and ground to air nuclear missiles were used to attack incoming bombers and it may be that the Aircraft Vulnerability program was used to estimate the vulnerability of NATO and Warsaw Pact bombers to such weapons.

Defense Nuclear Agency Blast Prediction Rule 1983

Cold War Blast Prediction Rule designed by Horizons Technology for the US Defense Nuclear Agency and manufactured by Perrygraf.

Atomic Artillery Weapons Effects Computer

From the early 1950s the US began developing nuclear artillery. The first  was the Honest John  missile with a range of 15 miles and  a W7 nuclear warhead with a yield of 20 kilotons. There was also the M65 Atomic Cannon delivering 280mm nuclear shells with yields of 15 to 20 kilotons. Both date from 1953.

280mm M65 Atomic Cannon

The first M65 was named Atomic Annie. On May 25, 1953, Annie fired an MK-9 atomic shell. It flew seven miles before exploding at a height of 524 feet above the ground.

Later systems included the Corporal missile, the M110 and M115 howitzers and the Davy Crockett missile.  The Davy Crockett had a disconcerting [to its users] range of only 1.25 to 2.5 miles and a yield equivalent to 10-20 tons of TNT.

W54 Nuclear Warhead for Davy Crockett

The MGR-3 Little John was a free flight artillery rocket system designed and put into service by the U.S. Army during the 1950s and 1960s. Carried on the XM34 rocket launcher, it could carry either nuclear or conventional warheads. It was primarily intended for use in airborne assault operations and to complement the heavier, self-propelled Honest John rocket systems. It had a W45 warhead with a yield of 1–10 kilotons of TNT.

The weapons were intended for US use in the western European battlefield.  Other countries also developed nuclear artillery.

Most of the training for the US systems appears to have been done at the Fort Sill Artillery School in Oklahoma.  The Atomic Artillery  Weapons Effects Computer shown below may have been produced  there.  A October 1958 school publication mentions the computer as being available from the Army Artillery and Missile School Bookstore.

The computer consists of three disks with two cursors. It is 14″ [355mm] in diameter and is made of some stiff material [probably card].

Atomic Artillery Weapons Effects Computer

For more posts about Cold War calculators click on the Cold War Calculators category on the right.