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보/고/서

ATIS INTERROGATION REPORT NO 3544　23 February 1951

FIELD REPORT (ADVATIS Sp Rpt 026)　12 February 1951

Well educated, cooperative. Judgement of distance poor. Memory good. Reliability - Good.

(1) PW was Elevation Angle Finder. PW trained 2 weeks as such at P’YONGYANG.

(2) Computer operated by ten men. See sketches No 6.

Computer crew’s duties: (See sketch #6 d for positions)

No. 1 Man - Estimated and corrected for wind velocity and direction. Also measured the distance (called BAZA) from computer to central distributor.

No. 2 Man - Calculates burst time.

No. 3 Man - Calculates elevation angle.

No. 4 Man - Calculates drift correction for shell.

No. 5 Man - Sets distance of a/c which is determined by base range finder operator.

No. 6 Man - Sights a/c horizontally through X-hair sights. Computer useless unless is on X-hair. Sighting crank connected to cylindrical graphs at No. 2, 3, &4 operators.

No. 7 & 8 Men - Set 2 identical dials by cranks. Purpose unknown. After dials are set both call “KYOLHAP” to indicate that they are ready.

No. 9 Man - Sights a/c vertically through X-hair sights. Turns crank to keep a/c in the X-hair sights. This crank is connected to cylindrical graph in front of No. 2, 3, &4 Operators.

(3) Computer made in USSR. PW operated a 1940 model.

(1) Equipment is USSR made.

(2) Antenna seems to revolve at a rate of 4 RPM.

(3) Power source: Portable motor (output unknown) supplied power to antennae via one cable.

(4) One cable (dia 1 cm, number of wires unk) led from antenna to computer. One cable led from computer to central distributor (　　), 4 individual lines leads from central distributor to the 4 gun sites.

(5) The radar antenna revolved 360°, no vertical movement of antennae.

(6) Radar antennae approx 30 m from gun sites.

(7) Radar site on a low level area. About 4 km S of P’YONGYANG.

(8) Four 85 mm AA guns per 2 antennae.

PW saw 3 or 4 men around transmitting antennae and one at the receiving antenna.

PW saw 10 Russians at Radar Site in mid-Sep. See sketch #5 for shoulder epaulets.

(1) Guns made in USSR.

(2) Four 85 mm AA guns per battery.

(3) 8 men per gun. Duties unknown.

(4) 85 mm AA gun pulled by vehicles.

(5) PW guesses it takes 5 minutes to prepare to fire when in prepared gun sites.

(6) Maximum range of shell, 8,000 m.

(7) Gun can be used for ground targets; direct fire.

(8) Burst radius of round is 50 m.

(9) No difference in accuracy observed in non-radar and radar batteries.

(10) Flak bursts around a/c. No direct hits observed.

(1) No. 10 Man - Starts and stops this computer. Amount of voltage required to operate computer unk. Also acts as crew chief.

(2) PW was elevation angle finder. Computed angle of elevation of aircraft.

(3) Range to aircraft not reasonable with computer. Range computed in meters by base range finder.

(4) Direction of aircraft spotted as such:

N as 1, E as 4, S as 3

W as 2, NW as 12, NE as 14

SW as 23, SE as 34, etc

Direction of aircraft is visually spotted by Plat Ldr who relays general direction to base range finder and computer. Method impractical on overcast days.

(5) Base range finder manually operated and computer operated by wet batteries. 4 x batteries connected in series, output approx 70 volts. There are not direct charging facilities, so wet batteries are replaced when voltage drops to 30 volts or less. There was a battery charger with the computer unit but PW never saw it in operation. Dimensions: 60 x 40m 50cm with 2 steel wheels, diameter 10cm.

(6) Rader not used with computer.

(7) Number of men operating director unknown.

(8) No test problems used to check accuracy of computer.

(9) Radar not used in PW battery. (Radar equipment seen by PW was of some unknown unit of NKA).

(10) A cable; dia 1 cm, number of wires 3; laid 10cm underground leads to a central distributor (Dimensions: 40 cm x 40 cm x 25 cm steel bar with 4 cm x 5 cm long steel legs). 4 individual lines lead from central distributor to the four 85 mm AA guns. Number of wires in each line unknown.

(11) No climatic difficulties in operating computer. (Rain, snow or heat).

(12) Performance of computer, poor. PW believes that computated results were inaccurate because computer appeared poorly constructed.

(13) All members are taught that the computer is an accurate instrument, but actual use indicated differently. All members share PW opinion.

(14) Manufactured in 1938 - 1940 period in USSR. External appearance is good, but computed results are poor.

(15) Meteorological data should be given for computation purposes but actually the man at the computer unit who measures horizontal distance to target merely estimates wind velocity and direction.

(16) Visual spotter on small knoll verbally alerts company commander who in turn blows a whistle to the 3 plat ldr. Plat ldr verbally alert their plat. One phone connected with other batteries and Bn Hq. Alert was called several times over the phone.

(17) Guns were manually laid.

Wet cell batteries in the computer were changed every 2 days. Barrel of 85 mm becomes dull red during sustained fire causing inaccuracy.

BATTERY SITE AT P’YONGYANG(OBS: 2 Aug 50 to 15 Aug 50)

NOTE: All wires between #1, #2 and #3 were buried 10cm underground.

1. 85mm AA gun sites

2. Central distributors

3. Computers

4. Base range finders

5. Bakery

6. Rotary

7. TAEDONG vehicle bridge (damaged)

8. RR bridge (damaged)

9. Portable generator

10. MORANBON mountain

11. Substitute bridge (wooden)

12. Hangar (?)

13. Sodded runway

BATTERY SITE APPROX 40km SE OF P’YONGYANG(OBS: 18 Oct 50 to 19 Oct 50)

NOTE: Emplacement details identical with those in Sketch - 1

1. 85mm AA guns

2. Central distributor

3. Computer

4. Base range finder

5. Pine trees (10 to 15)

6. Small village-name unknown

7. National road: 2 lane, gravel

RADAR BATTERY SITE AT VICINITY OF P’YONGYNAG(OBS: As of Sep 50)

1. Power plant

2. Antenna (transmitter)

3. Antenna (receiver)

4. Base range finder

5. Computer

6. Central distributor

7. 85mm AA guns

8. Christian church

9. Bakery

10. Steel RR bridge

11. TAEDONG vehicle bridge

12. Village, name unknown

13. Battery sites (see Sketch - 1)

14. P’YONGYANG airfield

15. Tent

16. Wooden bridge

SKETCH OF RADAR ANTENNA(Observed from a distance of 15m)

1. Porcelain insulators

2. Steel bar (approx 1” dia)

3. 1m square entrance

4. Cone (inside unknown)

This was identical to (A) Receiver antenna, except without the steel cross bars on top.

SKETCH OF RUSSIAN SHOULDER EPAULET(CBS: Middle of Sep 50 at P’YONGYANG)

NOTE: PW insists that stars were as shown, and not beside each other. He also clearly remembered that 2 red stripes as shown were observed.

PW gave the following information concerning one of the persons who were this type of epaulet.

NAME: Unknown

NATIONALITY: Russian

POSITION: advisor (hearsay)

AGE: about 40

HEIGHT: 1.8m

WEIGHT: 60kg

BUILD: Heavy

COMPLEXION: White

LAST SEEN: (Location) 8km S of P’YONGYANG　Middle Sep 50

REMARKS: The above figures are all approx. This man was seen only twice by the PW. He wore blue trousers, OD color blouse and cavalry boots on both occasions.

THREE VIEWS OF THE COMPUTER

TWO VIEWS OF THE COMPUTER

THREE VIEWS OF COMPUTER

Hatched area, Door, Wet-cell batteries inside. Hinges bottom.

Hatched area, Door - content unknown. Hinges top.

Box - hatched area lid, hinges towards trailer hitch.

TOP VIEW OF COMPUTER

(See attached report for duties)

SKETCH OF SIDE VIEW OF PANEL #2

1. Crank: dia 6cm, for Item #2

2. Dial: dia 5cm (height dial), details Unk.

3. Laying gear (training gear) sight

4. Laying gear (training gear) scope

5. Lens in laying gear (training gear) sight dia 5cm

6. Knob (dia 15cm) for turning Item #4; 360 degrees revolution

NOTE: Dimensions of #3 & #5 are same as Item #9 & #10 of Panel1 #1, on following sketch.

SKETCH OF PANEL #1

1. 6cm dia knob; (for #2 operator’s graph (see item # sketch 6e))

2. #2 operator’s graph, behind glass pane

3 & 4. Same as Item #1, for operation of Item #5(operator #1)

5. Wind and “Sujongki” dial. No further info. 25cm dia, black face, red cross lines, numerals in white.

6. Dial - no further info. 5cm dia

7. Dial - 5cm dia. No further info

8. Crank; 15cm dia for turning Item #10 (see item #1 sketch 6 e)

9. Training gear sight

10. Laying gear (training gear) scope

11. Sighting lens, dia 5cm

SKETCH OF PANEL #3

1. #3 operator’s cylindrical graph behind glass pane

2. 6cm dia crank for Item #1

3. #4 operator’s cylindrical graph behind glass pane

4. 6cm dia crank for Item #3

5, 6 & 7. 5cm dia meter/dial further info unknown. Small white triangle at top of each dial

8. 5cm dia meter/dial scale on edge, no further info available

9. Correcting board (修正板) one end plus other minus range unknown. Sliding indicator. 8cm long, 2cm wide, glass pane over sliding indicator

10. Laying gear (training gear) sight

11. Laying gear (training gear) scope

FRONT VIEW OF PANEL #4

1. &3. “KETSUGCHAN” (結合板), 10cm dia, 8cm needle 1cm triangles (No. unknown). No further info.

2. &4. 6cm dia knob/crank for Items 1 &3.

5. Correcting board (修正板), 10cm long, 3cm wide. Scale, left side, range unknown. Indicator to right of scale behind glass pane. Further info unknown.

TOP VIEW OF PANEL #5

1, 2, 3 &4. Levels, each 4x5cm. Placed 2 or 3cm from edges in each corner. Cross-hair lines each.

5 & 6. Training gear scope. Placed 7.5cm from edges of corners.

SKETCH OF OPERATOR #3 COMPUTING GRAPH

Cylindrical graph - spacing gradually decreases going upward.

Spacing between lines - parallel.

(Dimensions of #2 & #4 operators’ computing graph were similar to above. Scale of #2 & #4 operators’ equipment were unknown. Cylindrical graph of #2 operator’s has cross graph lines, one black, other red.)

Sliding indicator is set on figure on cylinder to show gun barrel angle on vertical scale.

For the Commanding Officer: