3rd Leuchter ReportThe following is the text of the Eaton Proposal for the Mississippi Lethal Gas Chamber



Chamber shall be of hexagon shape, fabricated from steel plate conforming to A.S.T.M. Specifications No. A-283, Grade "C" of sufficient thickness to withstand the pressure of the generated gas and the vacuum induced by the exhaust fan. Chamber to be complete with necessary windows and door, gas generating equipment, proper neutralizing equipment, execution chair, valves, and all necessary accessories to insure a positive and rapid execution without danger to operators or witnesses.


A self-contained hydrogen Cyanide generator, equipped with all necessary valves, levers, pressure gauge, etc., for introducing and controlling the flow of the generated gas into the chamber. Complete with necessary neutralizing agent inducing equipment properly attached so that exhaust gas generating materials can be flushed out of the generator, with water into the sewer connection after execution has been completed. All the above to be directly beneath the chamber, in a basement room, provided by the Purchaser.


Chamber shall be equipped with suitable chair provided with proper arm and leg shackle attachments for securing prisoner in proper position in chair.


Chamber shall be equipped with proper ventilation including manifold, with special ports spaced at proper intervals to insure rapid admission of a neutralizer vapor into the chamber through a controlled system of valves.


Chamber to be equipped with a high volume, electrically driven exhaust fan capable of completely exhausting the chamber in 90 seconds. Fan mounting to be complete with quick acting large area exhaust valve with controls to operating point. Inside lights to be vapor proof, of sufficient size to properly flood chamber.


Installed in the walls of the chamber shall be five windows of bullet proof glass. One window at the executioner's station and four windows located in the witness room. All windows to be properly gasketed so that they will be gas tight. A quick acting bulkhead type door shall be furnished with special designed hinges and locking hardware to insure continuous gas tight operation without damage to gaskets. All gaskets (windows and doors) shall be impervious and resistant to the generated gas and shall fit into the retainer frame so as to insure perfect alignment and tightness, regardless of temperature changes.


All operating controls, including switches, venturi tube, etc., shall be brought to a point near the executioner's window for convenient and positive operation.


Interior to be painted with a metallic, acid resisting, light color paint.


Chamber enclosure building, including all necessary electric power, water, and sewer connections, will be furnished by the Purchaser.


Chamber must be properly tested in presence of the Warden, and proven effective and safe.


To be assured of tightness of fluid service lines and gas generator bowl first observe Drawing A-2249 attached.

Now open completely valves 3 and 4. Then turn on water at spigot above mixing vat 9 and allow water to run through the system for about 5 minutes. This will insure that the lines are clear from the mixing vat to the generator in the bottom of the chamber and that the drain from the gas generator to the sewer is perfectly clear.

Then close valve 3 which shuts off the line to the sewer, allowing the water to fill the generator to chamber floor level. Then enter pit beneath chamber and examine all lines, as well as bottom of the generator to be sure that all piping is tight.

Then close valve 10 while water is still at floor level.

Then open valve 3 and allow water underneath valve 10 to drain to sewer, trapping the water above valve 10.

Then close chamber tightly, including exhaust valve 2, putting a little water around exhaust valve 2 to insure tightness, and start exhaust fan, opening valve 5 in top of chamber, thereby pulling vacuum on chamber where it can be observed whether there is any chance of gas leakage around valve 10 in bottom of chamber. If a constant vacuum is shown on vacuum gauge 6, this assures that the chamber is tight in every respect.

After chamber has been proven tight, and just before an execution, the following procedure should be accomplished: At least two gallons of distilled water should be flushed through the system by pouring it into mixing chamber 9 and allowing it to run through to fill up traps in the piping system.

Then valve 3 should be closed permanently and valve 4 should be closed to hold back the acid and distilled water which will be mixed in the mixing chamber 9.

Valve 10 should be in the closed position and the cyanide should be placed in the receptacle above valve 10 just prior to the time the victim is placed in the chamber.

The acid should be mixed into the distilled water at the time the death sentence is being read to the victim, for the reason that better results are obtained in the generation of gas from the hot acid and water mixture.

As the victim is being strapped into the chamber, valve 4 should be opened allowing the mixed acid and water to drop into the generating chamber. When all the mixed acid and water has dropped into the generating chamber, valve 4 should then be closed tightly and the mixing chamber 9 should be filled entirely with water from the spigot above this mixing chamber. Ammonia chambers, which have been previously filled, then should be put in readiness for operation. It is, of course, understood that valve 2 which is the intake valve, should be closed at all times, with the exception of when exhausting the chamber after the execution has been completed.

Sheet # 2

With the ammonia injectors ready, with valves 3 and 4 closed, with the acid in the bottom of the gas generator, and with the cyanide in the container above valve 10, the victim in the chair and the door properly closed and sealed, the chamber is ready to perform the execution. Valve 5 should be closed and the fan running. All that is left to do is pull lever 1, which opens valve 10 above the gas generator, allowing the cyanide to drop into the acid. You then immediately get gas.

Have the operator constantly watch the vacuum gauge 6 to be sure that during the time of the execution the chamber is under vacuum.

When it has been determined that the victim has expired, then lever 1, operating valve 10, should be put in the closed position thereby isolating further gas going into the chamber.

Then valve 5 is to be opened wide, then valve 2 is to be opened wide, and the ammonia injector No. 7 opened into the intake passage to neutralize the gas and raise it into the exhaust. The chamber should be completely cleared within one minute.

While the exhausting of the gas in the chamber is being accomplished, valve 3 is to be opened allowing the acid and the residue from the cyanide to pass into the sewer.

Valve 4 is immediately opened after valve 3, allowing the water which has been placed in mixing chamber 9 to drop into the gas generator, flushing same completely through to the sewer. In flushing this water through it is, of course, understood that the ammonia injector in the mixing room be opened into the flush line to go through the system with the flush water. The water valve above the mixing pot can be opened to accomplish continual flushing during the same period of time as the chamber is being exhausted.

If there is to be two or more executions simultaneously, it should be noted that after the flushing with ordinary water which has had ammonia contained in it, should be completely flushed out of the system by a repeat of the flushing of the system with distilled water to eliminate ordinary water with ammonia which will be caught in the traps.

The second execution can be accomplished by repeating the procedure for the first operation.

For record purposes, the amount of distilled water required is 6 quarts. The amount of acid is 6 pints. The amount of cyanide is 16 ounces, and the cyanide should be in 1/2 oz. pellets.

After each execution the inside of the chamber should be thoroughly washed down and allowed to dry out, and the door gasket should be greased with vaseline. Valves 3 and 4 should be left in the open position.

This, we believe, covers the full testing, operational and final cleanup of this apparatus.

In terms of weight the total mix in mixing bowl and trap combined will then be: Water in trap, 40 oz. 2.5# Measured water to mixing bowl 9.5# Measured acid to mixing bowl 7.0# Total 19.0#

Concentration 7.3 equals 37.5% 19.0#

Prior to the actual execution the water and acid should be measured out and held in separate containers ready to mix together in the acid mixing hopper. The actual mixing is to be done 10 minutes prior to the time it must be released to the chamber acid receptacle.

In a single execution one mix shall be used and released to the receptacle, under the particular chair to be used. In a double execution two mixes shall be used and released to the receptacles under each of the two chairs.

2. Sodium Cyanide - One pound of sodium cyanide shall be used with each acid mix. In a single execution one pound of sodium cyanide in appropriate gauze bag shall be immersed in the receptacle under the particular chair used. In a double execution one pound of sodium cyanide in appropriate gauze bag shall be immersed in the receptacle under each of the two chairs.

RULES FOR OPERATION OF CHAMBER Preliminary preparation:

1. Inspect thoroughly and test the chamber and all piping above and below floor.

2. Assign operatives to duties and rehearse so that each is absolutely familiar with his duties.

3. Measure the distilled water and acid required for the execution and place in separate containers ready for actual use. DO NOT MIX ACID AND WATER AT THIS TIME. USE RUBBER GLOVES IN HANDLING ACID.

4. Place sodium cyanide in gauze sack properly tied and ready to attach to chair. PUT AWAY IN A CONVENIENT PLACE TO ELIMINATE DANGER UNTIL NEEDED. KEEP AWAY FROM ACID.

5. Fill ammonia containers for air flushing and water flushing systems with ammonia.

6. Turn on all necessary lights in chamber and rooms to be used in connection with execution.

7. Turn on ventilation fans for witness areas.

8. Turn on chamber exhaust fan.

9. See that chamber exhaust valve 3 is closed.

Return to Leuchter Report Table of Contents