Camera course notebook

MBubbGJ1477939-160322-02.pdf

Title

Camera course notebook

Description

64 pages of course notes. Inside front page ' Bubb G J 1477939, Entry 35, Berryfields, Melksham, Sept 2-21 1943' Contains information of batteries and motors in general then specific notes on F24 camera and controls, night photography MkIII, torpedo training camera type F46, cine camera gun G45. Last page has hand-drawn colour cartoon figure of camera gremlin.

Creator

Publisher

IBCC Digital Archive

Contributor

Sue Smith
Karl Williams
David Bloomfield
Trevor Hardcastle
Tricia Marshall

Rights

This content is available under a CC BY-NC 4.0 International license (Creative Commons Attribution-NonCommercial 4.0). It has been published ‘as is’ and may contain inaccuracies or culturally inappropriate references that do not necessarily reflect the official policy or position of the University of Lincoln or the International Bomber Command Centre. For more information, visit https://creativecommons.org/licenses/by-nc/4.0/ and https://ibccdigitalarchive.lincoln.ac.uk/omeka/legal.

Format

Cover and 32 double page notebook

Language

Identifier

MBubbGJ1477939-160322-02

Coverage

Temporal Coverage

Transcription

[underlined] BUBB. G.J. [/underlined]
1477939-020001
[page break]
BUBB. G.J. 1477939
ENTRY 35.
BERRYFIELDS, MELKSHAM. SEPT 2.21 1943.
[underlined] CAMERA COURSE [/underlined]
[page break]
Formula for batteries
BATTERIES
Formula [underlined] LEAD. ACID CELL [/underlined]
Formula [underlined] CHARGED [/underlined]
Formula for [underlined] DISCHARGED [/underlined]
Formula for [underlined] ALKALINE CELL [underlined]
[page break]
[underlined] Batteries [/underlined] or [underlined] Accumulators [/underlined] are used for storing electrical energy in the form known as. D.C. the capacity of the battery is the quantity of energy it can store and is expressed as ampere hours. There are two common types of storage batteries – [underlined] lead acid [/underlined] having lead plates with diluted sulphuric acid as electrolite [sic] . – the [underlined] Alkaline [/underlined] type having nickel and cadmium or nickel and iron plates with caustic potash as electrolite [sic] ([underlined] caustic potash [/underlined] is supplied as a granulated powder or solid and is a caustic.)
[underlined] Lead Acid [/underlined] . The battery consists of several cells, each cell having a number of plates spaced alternatively positive and negative with their pieces of insulating material between them, each positive plate in a cell is connected to one
[page break]
terminal and each negative is connected to the other terminal. The cells in the battery are connected by metal strips [underlined] in series [/underlined] (positive to negative) when charged positive plates are charged chemically into [underlined] lead peroxide [/underlined] and in colour a deep reddish brown. The negative plates become [underlined] salt lead caused [/underlined] spongy lead [/underlined] coloured silvery grey. The electrolite [sic] should have a specific gravity between 1.27O – 1.285 according to type, when discharged all the plates are changed to [underlined] lead sulphate [/underlined], a dirty grey in colour, the specific gravity of the electrolite [sic] has now fallen to 1.150, the voltage of a single cell on open circuit will vary between 2.3 volts charged and 1.8 volts when discharged, so that a 12 volt battery when fully
[page break]
charged, will read on open circuit 13.8 volts and when discharged 10.8 volts. Cells must never be discharged below 1.8 volts.
[underlined] Charging [/underlined]
The capacity of a lead acid battery is usually given at a 10 hr rate for a continuous discharge so that a 12 volt 4O A.H. battery should give for 10 hrs 4 amps of current and the battery should not be charged at a higher rate than 4 amps, unless there are special instructions. Capacity depends upon surface area of positive plates and is roughly .04 amps per square inch. Positive plate always has negative each side. Voltage to allow for the charging is 2.5 volts per cell. Temperature during charging should not exceed 100 ̊ F, if it does it reduces the current The battery
[page break]
is fully charged when each cell in it has maintained for about 1 hr the correct S.G. and P.D of 2.7 volts obtained whilst the cell is charging. Batteries must only be charged in series. Before charging check level of electrolyte in each cell, this should be at least 3/16” above the plates, top up with pure distilled water only. Keep vents clear. The advantages of a lead –acid battery are. Low internal resistance giving high P.D.
Big capacity relative to weight and size
[underlined] Do not [/underlined] short circuit, heavily discharge for long periods, discharge below 1.8 volts or S.G. 1.150, charge too fast, treat rough or leave in a discharged condition for any length of time.
[page break]
[underline] Alkaline Cells [/underlined] . positive plates – nickel oxide and negative cadmium and or iron. Containers are welded steel with terminals fitted in insulated collars, to prevent short circuiting. The electrolyte is a solution of caustic potash and pure distilled water to a S.G of 1.190 when fresh. S.G. does not change with charge and discharge so it is no indication of the batteries condition. After about 18 months the S.G. will have fallen to 1.160 it is then poured away the cells rinsed out with pure water and refilled with fresh solution. The voltage of a single alkaline cell on open circuit will vary between 1.4 volts charged and 1.1 volts discharged.
[underlined] Charging [/underlined] is done similarly as the lead acid cell, but is accomplished at higher amperage.
[page break]
Normal charging amperage is stated on makers label and varies with design. A safe rate is 1 ½ times the capacity divided by eight. The battery is fully charged when each cell has maintained for an hour a P.D. of 1. 7 volts. Top up with distilled water, keep vents clear, allow 1.5 volts to charge it.
Advantages, high rates of charge and discharge possible without harm, no deterioration if left discharged for some time, strong construction giving longer life
[page break]
[underlined] MOTORS. [/underlined]
Simple electric motor consists of a curved permenant [sic] magnet, known as the [underlined] field magnet. [/underlined] Between the poles is a shaft free to notate on bearings, on the shaft is a [underlined] ‘former’ [/underlined] upon which wire is wound, this is the [underlined] armature [/underlined] the ends of the armature windings are attached to brass segments, forming a collar around the shaft these are the commutators, each segment is electrically insulated from the others and current is fed to the segments and so through the armature by brushes of coppered carbon or other suitable substance. When current is switched on the combined magnetic fields cause rotation of the shaft, its speed depending on the voltage supply and load reversing the supply polarity will reverse the motor. Because the field of strength in the permenant [sic] magnets cannot
[page break]
be made very large and decreases with time a strong magnetic field is produced by coils of wire, wound round an iron core. In a series wound motor the field coil and the armature windings are in series. The characteristics in a series motor are, big starting torque, speed variable with load or voltage variation, but is good for a steady load. In a shunt wound motor the field coil and armature windings are connected in parallel to each other, this gives a different characteristic to the series motor as follows, small starting torque, steady speed, irrespective of slight current variation or of load. From then it will be seen that a series motor is very suitable for photography where immediate high operating speed is necessary and the load on the motor is steady. The series motor
[page break]
used in the F.24 and G.45 cameras have a speed of 6,000 revs per minute and, 5,700 revs per minute respectively The shunt motor is used in the Torpedo Training Camera F.46 at 6,500 R.P.M. and the T.35 Electrically controlled at 3,500 – 4000 RPM.
[underlined] Care and maintenance [/underlined] of electric motors consists of bearing lubrication cleaning the commutators and renewing or adjusting the brushes combined with general cleanliness. In camera the lubrication should be as little as possible, surplus oil always being wiped off, the commutator can be cleaned with a soft cloth and motor spirit or meths, aviation spirit is not to be used, brushes require little attention, but when renewed make sure that good contact is made. G 45 camera motor has a type of centrifugal governor, which operates a switch
[page break]
cutting in a resistance and limiting the motor speed. There are two adjustments one coarse and one fine, the coarse adjustment should not need tension after leaving the depot or works, it is regulated by altering the tension of a spring controlling the C.F. weight. Increased compression of the spring requires more R.PM to throw out the weight and produce the movement which separates the spring contacts.
[underlined] Fine Adjustment [/underlined] – is by grub screw to set the position of the fixed contacts, this needs only about a ¼ of a turn.
[underlined] F 24 Motor Maintenance [/underlined] – bearings examined and oiled every six months every 12 months partly dismantle clean casing, examine brushes, renew if down to 3/8 nh or less, the friction clutch of F.24 motor adjust by the spring compression between two drums
[page break]
when motor shaft is held, the extension shaft can, by an effort, be turned by hand
[underlined] F46 Motor Maintenance. [/underlined] one drop of oil in top bearing weekly, monthly if camera not in use, examine brushes
[page break]
[underlined] AIR – CAMERA. F. 24 [/underlined]
This camera may be used as “hand held” or fixed camera having various mountings as follows,
[underlined] Type 16 [/underlined] for flying boats, hand or electrical operation, stows on the bracket and can be hand held or mounted on a bracket outside the hole in use camera secured in mounting by two spindle ended screws, has adjustable handgrips and trigger release, tubular sights.
[underlined] Type 21 [/underlined]
has two adjustable handgrips and trigger release, tubular or frame sights for 8” cone interchangeable stows in frame.
[underlined] Type 25 [/underlined] . for mounting on camera rails in aircraft, camera secures y screws. camera will tilt and lock in a gimble system – fitted with levels and fore and aft scales.
[page break]
has big shock absorbers, quick release fitting and drift scale
[underlined] Type 24 [/underlined] – similar, smaller, going out of date.
[underlined] Type 26 [/underlined] – similar to 25, but has extension arms giving clearance for oblique photography and long cones
[underlined] F24 [/underlined] is used for either vertical or oblique photography and with an electrical timing control for making ‘mosaics’, the camera is made on the unit system for interchangeability of parts – these parts are, the [underlined] body magazine, shutter, gear-box [/underlined] and [underlined] lens cone [/underlined]
[underlined] Camera body. [/underlined] – houses the shutter frame and provides a mounting for the magazine, lens cone, and gear-box and includes the register glass
[underlined] Magazine [/underlined] – houses the spools of exposed and un-exposed films it has
[page break]
two parts, the spool carrier and the magazine couple, the mechanism for releasing film during winding for measuring and operating an exposure counter and film wind indicator are part of the spool carrier the cover makes the assembly light-proof, except for the aperture left for making the exposure, which is covered on the inside by the pressure [inserted] pad [/inserted] exposures are 5” square with a 3/16” margin for clearance 125 exposures are made on 56 feet of film, loaded in a dark room. The pressure pad is supported by a bar secured to it by a hinge, the bar is hinged at one end and has a projecting piece at the other end, this piece goes through a slot in the magazine and rests on the meshing lever. Light proofing of the slot is obtained by two large steel washers having between them a felt pad and
[page break]
a spring. Pressure is adjusted by moving an end of the spring along the toothed rack below the pressure bar. Feed spool roller has an adjustable friction loader, the receive spool roller is geared to the film measuring roller and has a friction drive.
[underlined] Magazine Friction Test [/underlined] – have magazine level and spare spool in receive side, put tester between feed spool holders with its weight at feed and arm at right . angles and away from feed adjust tension so that arm will just fall from horizontal with light tapping. Testing receive spool holder, the weight is put to “receive” and arm at right angles over the bridge, spare spool in feed side, adjust friction drive so that when turned by measuring roller gear, the weight arm just
[page break]
lifts and falls again
[underlined] Universal Shutter Mk I [/underlined]
Is a fixed slit variable speed focal plane self capping type. Two interchangeable blinds are supplied and are easily changed by sliding the brass rod at each end through the slot in the correct roller and then making adjustments The blinds are, [underlined] Type B. [/underlined] 3/8” slit, exposure speed 1/150 – 1/300 of a sec. [underlined] Type C [/underlined] 3/16” slit, exposure 1/350th – 1/500th of a sec. Adjustments on main blind, when replacing worn blind or changing blind. A) Initial tension 15 turns counter clock. B) With trailing edge of blind 90 ̊ over pinion roller when in set position, the toe of the brake lever should be in the root of the cam, allow to run back and toe should be on the highest part of the cam. C) Anti-acceleration spring tension – disengage
[page break]
A.A. gear wheel from pinion and release tension, re tension gear – wheel anti-clockwise a ¼ turn for B, 1 ¼ turns for C – re-engage gear and pinion. Pinion fractions should not slip when drawing blinds, but can be by hand if roll is held.
[underlined Capping Blind [/underlined] . Tension with 6 turns of roller spindle anti-clockwise. Blinds should be renewed when cracks or wear on material begins to show light.
[underlined] Gear-Box [/underlined] . has the following component. worm wheel with spring clutch gap wheel with cam and contact plate, driving pinion, handle with snail clutch, locking lever, locating lever, meshing lever, release block and post main blind pinion locking post. A worm gear driven by flexible drive operates the gear box when power is used. Adjustments :- by eccentric bear of meshing lever, if
[page break]
all other points easy running, 2.) of locating pin by eccentric bearing
[underlined] Lens Cable [/underlined] – mounts the lens the correct distance from focal plane and has mechanism for adjusting the diaphragm opening sizes 3 ¼” & 5” wide angle, 8” 10” 12” & 14” and tele-photo 20”, 30”, 36” & 40”. Capital F usual indicates focal length and indicates the cone’s size, F/2.9 = stop number = [underlined] FOCAL LENGTH APERTURE [/underlined]
[underlined] Testing [/underlined] (1). Load camera with complete length of waste film, having 100 exposures on receive spool operate 6 exposures. (3.) Remove magazine and pencil line across aperture H. (4) Fit magazine and operate once, pencil again as in (3) and so on to end of film (5) Unload and measure overlap of marked spaces, this must not exceed a ¼” if variable or camera fails to wind over last few feet that remain tension is incorrect. Ref.. 1355 Vol 1 Part 2 Chapter 1. Para 76-93 for [underlined] Maintenance [/underlined]
[page break]
[underlined] Push switch control [/underlined] is used for remote operation of the camera from the cock-pit or observers position. This has a feeder type counter and a green lamp to show camera re-wind.
[underlined] RUNNING FAULTS [/underlined]
(1.).[underlined] NO EXPOSURE MADE AND FILM NOT WOUND [/underlined]
Indicated by failure of green lamp in electrical control to light. or, when hand or semi. automatic operation, by film wind indicator failing to rotate.
1.). Magazine fouling meshing lever.
2.). Faulty or broken spring tooth.
3.). Broken meshing lever spring.
4.). Broken release post spring.
5.). Faulty timing or push button switch in electrical control.
II.). [underlined] EXPOSURE MADE BUT FILM WOUND [/underlined]
1.) Broken spring in main or capping blinds.
[page break]
Graph of [underlined] F.24 TYPE E. GEAR-BOX. DUAL VOLTAGE [/underlined]
[page break]
2.). Main blind pinion slipping.
3.). Failure of spring post of locking lever to hold the shutter in the wound position when hand operated.
3.). [underlined] CAMERA. “RUNAWAY” [/underlined]
Indicated by continuous rotation of film wind indicator or continuous burning of green lamp.
1.). Broken spring on locking lever
2) Failure of time switch in control box.
3.) Push button or switch jammed
4.) [underlined] MOTOR FAILING TO OPERATE CAMERA [/underlined]
Indicated by failure of film wind indicator to rotate on power, but can be operated by hand.
1.). Broken or faulty clutch spring on worm wheel.
2). Faulty motor or clutch in motor
3). Broken pin on worm in camera or motor driving shaft.
5.) [underlined] INCORRECT SPACING OF NEGATIVES [/underlined]
1.). Incorrect tension on feed or receive spool pinions.
[page break]
2). Damaged film spool
3.) Failure of locating lever spring.
[underlined] T.35. ELECTRICAL CONTROL OF. F 24 [/underlined]
This is to enable photographs to be taken at pre-determined intervals of time, range of time interval is from 2 secs to 50 secs being controlled by [underlined] interval setting [/underlined] knob which moves over a scale. The control is mounted on a cast base and is made up of units designed for easy dismantling necessary wiring from the plugs is in the base, circuit being made to the components by spring contacts. Units are :- (1) [underlined] The movement [/underlined] consisting of a DC shunt motor coupled through a friction drive to an escapement which is geared to the timing wheels. A push [underlined] exposing button [/underlined], a [underlined] counter [/underlined]and [underlined] warning light contacts [/underlined] are on the same framework. (2) [underlined] The Base [/underlined]
[page break]
with plug connections, warning lights, pilot’s indicator lamp plug, and the wiring. (3) [underlined] The Main Switch [/underlined] with delayed action control and a safety switch. (4) [underlined] The Camera Contacts [/underlined] for operating camera release solenoid, there is a front cover and back with wedge fittings. (5) [underlined] The Timing Gear [/underlined] in the movement consists of an escapement, vibrating about 240 times per minute, (that is 120 oscillations) a brass outer case driven by a crown wheel from the motor and two timing wheels geared to a driving pinion on the escape wheel shaft, the front timing wheel turns anti-clockwise and the rear clockwise Between the timing wheels is the radius arm turning on the same bearings but free from the wheels, a triangular steel plate against each wheel acts as a friction loading between wheels
[page break]
and radius arm to take up play. The base of the radius arm is fitted with a metal shoe which works the delayed action on the main switch The top as a projecting steel pin at right angles through it (the wiping pin) Pivotted [sic] to the top of the radius arm are two catch claws at an angle of about 160 ̊ from each other so that when one claw engages with the teeth of the front timing wheel, the other is just clear of the rear wheel. Engagement of the claws is controlled by what is known as the heart shaped cam and trip plate, contacts in the form of spring buffers projecting up from the base of the radius arm close the red warning light circuit for about 4 secs. The heart shaped cam is operated by the trip plate which is spring loaded to each side of the
[page break]
radius arm, the plate is free to move up and down in the slot in the radius arm and also has side play so that it can rack the claw as it moves over the cam. With front catch claw engaged the radius arm will turn anti-clockwise till the trip plate comes up against a fixed stop which in some models is made capable of adjustment, the radius arm continuing it’s rotation a little, causes the trip plate to move over the cam on the claw shaft, which then pivots and disengages the front claw but engages the rear claw in the clockwise timing wheel. Radius arm moves clockwise until reaching the variable stop positioned by the interval setting knob, the time taken by the radius arm to travel from rest to the variable stop may be any interval between about 1 sec and 25 secs
[page break]
thus giving 2-50 secs complete cycle. The exposure contacts are closed by the wiping pin about 2 ½ secs after the warning light contacts are closed and remain closed for slightly over ½ sec. this action takes place [inserted] generally [/inserted] just after the radius arm has reached the fixed stop and begun to travel clockwise
graph for [underlined] TYPE 35 ELECTRICAL CONTROL OF F.24 CAMERA [/underlined]
[underlined] REAR VIEW [/underlined]
[underlined] The Main Switch [/underlined] has delayed action so that the machines arm will always stop in the same position, although the main switch was turned off some seconds before. In [one indecipherable word] model this ensures that as soon as the main switch is turned on an exposure will be made for the switch is spring loaded and has on the under side[sic] of the knob two dowel[?] holes which fit a peg on the body of the unit to turn on the switch, draw knob out and twist quickly 180º, allow to re-engage to prevent it returning by accident. If safety switch has been included in the circuit between exposure contacts and operating solenoids to counteract the closing[?] of the camera contacts if bumps[?] cause main switch to close or camera contacts to close, this does not affect the operation of the push switch. The push exposure switch is operated
[page break]

by pushing the white centre of the interval setting knob, this completes a circuit to the operating solenoid in the F.24 [one indecipherable word]box and makes one exposure re-winding camera ready for an other[sic].

[Diagram of camera mechanism?]

[page break]

[underlined] The Counter [/underlined] – is a large disc numbered around its edge from 0-125 by fives with a knob for resetting. The disc is mounted by a spring friction plate upon a free running gear wheel with 130 teeth. A lightly sprung [one indecipherable word] prevents the wheel turning backwards. In operation the wheel is turned one tooth at a time by a spring tension lever operated by the counter solenoid, the solenoid draws the lever back and the spring returns it and moves round the gear[?] wheel. The movement of the counter lever can be limited by loosening three screws and adjusting the [one indecipherable word] and eccentric stop respectively.
[underlined] Exposure Contact Unit [/underlined] - consists of one or two phosphor bronze strips bent over at the ends. The strips are fixed to metal blocks which are separately pivotted[sic] and tensioned by long springs mounted on the unit

[page break]

body. The block holding the shortest[?] strip pivots about the centre of its length while the other pivots about a 1/3rd from the top, this causes friction between the contacts which are situated at the back of the metal blocks being insulated from them with leads taken to an attached terminal block contacting steel spring strips at the base.
[underlined] Action [/underlined]
The [one indecipherable word] pin comes down on the bent part of the strip, bends them forward and slips through the “gate” cut in them . Wiping[?] pin now changes its direction and returns to press up on the bent over strip making the camera release contacts.
[underlined] Maintenance [/underlined] – contacts are all self-cleaned. Test for [one indecipherable word] and insulation – keep screws tight, lubricate very sparingly with anti-

[page break]

freeze[?] oil, keep a log book with running times, intervals, height and faults if any. Every three months or when required dismantle, clean and examine.

[underlined] N.B. [/underlined] Take care to adjust escapement if hair-spring has been loosed from balance staff or its end[?] unpinned. Impulse [inserted] pin [/inserted]dead between balance staff and pallet staff when spring normal.

[diagram]

[underlined] ESCAPEMENT MOVEMENT {/underlined]

[page break]

[vertically printed] [underlined] TYPE 35 No. 19 [/underlined]
[underlined] ELECTRICAL CONTROL OF F24 [/underlined]
[underlined] REAR VIEW [/underlined] [/vertically printed]

[diagram]

[page break]

[underlined] Y[?] 35: [/underlined] 15 & 6 two sec minium [sic] intervals for several cameras with distribution for P.R.U’s only. 11 & 12, 1y:18 now modified to 19 & 20.
[underlined] [one indecipherable word] 19 & 20 [/underlined] Are for use with night camera. Y.504 for altitudes between 2,000 ft & 22,000 ft. This control operates the electro. Magnetic release of the flare [one indecipherable word] so launching the flash at the instant the bomb release is operated and control started. A photograph of the area beneath (about 6,300 ft square from 10,000 ft height) is obtained about 6 secs before bomb impact, which is accurate enough for plotting the a/c position relative to the target, To prevent film “fogging” two frames are wound over about 8 secs before flash explosion and two frames, including exposure about 4 or 5 secs after flash explosion, failure of control or camera means that the aircrew

[page break]

will lack positive evidence of their success of attack. The differences are the camera contact phosphor bronze strip is re-shaped to contact on both transits of wiping pin and give time for two frames to be wound over by high speed gear-box. Push switch in knob for dial lumination. Single exposure main switch and solenoid operation. A plug and socket each for bomb release and flash release circuits. Fixed stop gives 12 sec interval between main contacts making on left hand transits. Red[?] warning flashes to show that flash is released. Green shows time for level altitude and connects to pilot’s indicator.

[underlined] Action [/underlined] Bombs and flash are released together and controls start clockwise notation to meet variable stop and returns after pre-set

[page break]

Interval, wiping pin closes camera contacts for about 2 ½ secs and camera winds over two[?] frames. Green light and pilot’s warning light glow. Trip plate reaches fixed[?] stop flash explodes about now and arm returns and after about 4 ½ secs makes camera contacts and operates camera winding over two frames, control switches off.

[underlined] Night Photography Mk[?] III – Simplified [/underlined]
The layout consists of – lens core with 8” focal length lens stopped to f2.9, aperture is always at that setting. A light [two indecipherable words] type is fitted to the base of the cone to prevent light from the exploding flash being directly thrown onto the film and ‘fogging’ it. Except for the shutter other parts are standard F.24 equipment. Control T35 19 & 20 is used and

[page break]

pilots indicator may have the word “level” shown in read.

[underlined] Procedure for Use [/underlined]
Test bench[?] to be level and camera mounting installed with camera levelled off or set to operational tilt, the angle being taken from table supplied, depending on height and speed. Give[?] several testing cycles in workshop and after installation [inserted] in A/c [/inserted] test again, first making certain that bombs are safe and/or bomb doors closed. That photo flash is not in shute and magazine if fitted, is not loaded – remove if loaded. Turn Y35 knob to start control, run a complete cycle and after fitting magazine wind over one frame by pressing release [one indecipherable word] (The photographer will have written start and a/c details on this exposure), before fitting magazine to a/c. A rubber draught excluder and heater[?] muff are fitted to camera, the

[page break]

muff is switched on when a/c is airborne. When bomb aimer intends to take the photograph he must put his No 3 shute flare selector switch to CAMERA” before pressing bomb release
[underlined] NOTE [/underlined] Variations in the use of the Universal shutter and type N [one indecipherable word] may be found in different Bomber Groups, but principle is similar

[page break]

[underlined] TORPEDO TRAINING CAMERA TYPE F.46 [/underlined]
Replaces P.39 for torpedo attack training and conformation of the results of the attack. The second special camera is mounted in the cock-pit to record photographically the instrument dials at the moment of release. This is the airspeed recording camera. The F.46 may be mounted in the wing on type 2Y mounting or may be under the fuselage or wing where special mounting type 30 is required Type 30 is a steel cradle to which type 2Y is bolted either above or below. If under-slung in the lower position the usual plain top plate of the camera is replaced for one with the dove tail fitting so that the camera is held by a stop grip. Type 30 mounting secures beneath the wing or fuselage to the lugs provided for the light series

[page break]

bomb racks which it replaces when the aircraft is on torpedo practice or attack. The F.46 is made up of interchangeable units, principal items being the body, lens heaters and optical flats magazine and mechanism panel which carries the motor and gearing, switches, wiring and shutter with its operating gear.
[underlined] The body [/underlined] is a strong casting having a lens mount in front, slides for the mechanism panel while the rear is cut away to make the aperture or focal plane. The surface of the aperture is burnished to provide a smooth face for the film to slide over. In the body are three spring contacts for the heater curcuit [sic] and watch lamp circuit. The watch holder fits in a slide beneath the body and is spring locked to it. On the side are the shutter manual control lever, the magazine catch and

[page break]

the safety catch for booth[sic]
[underlined] The lens [/underlined] is a [indecipherable symbol] 5’ wide angle with Extra Maginal [sic] Illumination (E.M.I.). This unit and heater assemblies are held in a tube which secures to the body by a flange, neither lens or mounting should be moved or disturbed from its position on the body. The [one indecipherable word] diaphragmets[?] adjust the aperture is between the lenses and the setting ring is bracketted [sic] to the outer setting ring which has a spring locating pin pressing into notches to hold the ring at the required aperture setting. Spring loaded plugs make the contacts for both heaters. The front heater is of cross-wires bedded on a ring of insulation, the rear heater has the element wound around slots in the periphery of the insulation ring, vents are cut in the ring to allow free

[page break]

circulation of the warm air. A thin piece of insulation is stuck round the ring to prevent electrical contact with the lens holder tube.
[underlined] The Front Heater [/underlined] consists of a clamp ring, shim ring, broad sealing washer of rubber or linotex, the filter flat, enamelled sealing washer and possibly packing ring or rings. If the clamp ring does not compress the sealing washer add packing rings. In the rear assembly are the retaining ring, clear optical flat, seating[?] ring and heater.

[underlined[ The magazine [/underlined] consists of the cover and bottom panel which supports all mechanism, is day light loaded, usually 4 exposes. The bridge piece on the panel mounts the pressure pad and spool holders. Three one-to-one gears form the drive from re-wind dogs[?] to receive spool, which has a spring loaded [one indecipherable word], coloured

[page break]

datum marks on the dog plates of both drives must be aligned with the datum on each unit before fitting magazine to body. The pressure plate should depress with the weight of over 1 ½ lbs but under 2. Flat[?] friction spring bearings and each spool should be adjusted to give even feeding from the feed spool without slack and reasonably tight winding on the receive spool.

[underlined] The mechanism panel [/underlined] forms the left hand side of the body and part of the base where the gear frame to the film re-wind dogs is positioned. On the side is the Y pin plug. The front of the [inserted] panel [/inserted] supports the [inserted]motor [/inserted] [one indecipherable word] type shutter and mechanism. The side of panel holds the release solenoid and bracket for part of the gearing, whilst the remainder of the gearing is on the bottom

[page break]

panel, with the change-over switch and three knife contacts for the heaters and watch lamp circuits. The connections engage when panel is pushed in and screwed up. The shunt motor (6,500 RPM) mounts vertically and drives a twelve toothed pinion, through a loose self-aligning coupling. Motor can be withdrawn without touching the gearing, brushes and [one indecipherable word] are visible for inspection and a shield is fitted around to prevent sparks fogging the film. Epicyclic [?] gearing gives reduction of 1400-1. Re-wind dog-wheel 4 revs in about 51 secs loaded.

[underlined] The shutter [/underlined] is a louvre type operated by a solenoid, the blades are grooved on one edge with a strand of wool stuck in for light proofing. A spring loaded rack turns the blades 90° to spin the shutter, the rack being depressed by a spring

[page break]

panel[?] on the solenoid carriage. As the blades reach the open position the panel[?] is tripped by an adjustable trip rod, so allowing the shutter to close. Exposure time is about 1/100th of a sec. and cannot be adjusted to much less without great loss of light and intensity. When the armature reaches its’ full travel, it closes a pair of contacts known as the release switch the exact instant of closure can be adjusted by means of a screw bearing on the lower contact so as to vary the distance between them these operate the release solenoid. The change-over switch before and during operation keep the motor contacts open and the shutter lamp circuit closed. When the release solenoid operates it allows a cam to turn under the spring pressure of the set-off lever

[page break]

this forces the switch lever out of the cam depression and operates the change-over switch to break the shutter contacts and make the motor contacts, motor starts and re-wind continues for one revolution of the cam. When the switch lever again drops into the cam depression motor circuit breaks, shutter and lamp circuit makes at change-over switch, release solenoid armature has locked the cam and camera is ready for further exposure.

The above sequence of operations is begun by pressing the torpedo release switch so energising the solenoid and watch lamp circuits, at the same time a second parallel circuit exposes the [underlined] air-speed recording camera [/underlined] in the cock-pit, this photographs the A.S.I and other instrument so recording their readings at instant of release. This small camera takes

[page break]

a picture 1½” x 1” on standard 35mm 8 exposure film. F 4.5 for mk I and 5.6 mk II they will focus to a minimum distance of 4 feet for nearer objects put scale to 4 feet, remove set screw from lens mount and turn lens mount anti-clockwise the distance stated in the table in A.P.1355 vol II B.34. A special holder for this camera has solenoid release arm. Re-wind of camera 1½ complete turns of winding handle. [underlined] The test adaptor [/underlined] is a skeleton magazine cover so that film wind can be watched. Film should wind over evenly and should not rock the pressure pad, if it does gently adjust the spring tension pressing the film on the spools. A sighting unit is for harmonizing the camera with the torpedo aiming sights. It is in two parts, framed ground glass screen and a plain mirror set at

[page break]

45° in a mounting which slides into the frame. A vertical hair line is ground on the glass for centering [sic] [underlined] Installation and Maintenance [/underlined] 1355 vol I Part II [one indecipherable word] Y 83.85 para. And 91.96

[page break]

[underlined] CINÉ CAMERA GUN G 45 [/underlined]
[detailed diagram]

[page break]

This can be used with suitable mountings in place of any existing British aircraft Machine Gun for training as for recording actual combat.

[circled] 1 [/circled] With type 2Y wing mounting and 32 adaptor plate in place of a fixed gun [circled] 2 [/circled] With type 29 mounting and 32 adaptor plate in place of Dickens[?] gas-operated m. gun
[circled]3 [/circled] With type 31 adaptor plate and modified gun-handle and switch mounts on the V.G.O. [one indecipherable word] in place of the magazine. [circled] 4 [/circled] With 33, 34 & 35 adaptors it replaces usually the upper right hand Browning in [two indecipherable words] type 4, Boulton-Paul and F.h type 16 Turrets respectively

Extensions lenses are always used in turrets with F.2”. Cameras in 12 & 24 volts – 18 having red label.
G.45 builds up in 10 units some [one indecipherable word] inter-changeable with similar units

[page break]

of same voltage. The body with gears lens unit and claw unit are not inter-changeable.
[underlined] The [circled]1 [/circled] body and [circled] 2 [/circled] lens units are optically matched to each other and must not be otherwise fitted to different ones. Lenses are of 2”, 2.2” or 2.4”. indicated by coloured bands on mounting yellow for 2” green 2.2” red for 2.4” all have f 3.5 and an infinity of over 30 ft. G.45B has optional stop f.6.3all lenses are fitted with heaters.
[circled] 3 [/circled] [underlined]Magazine container [/underlined] is hinged at top of body and can be loaded from top or through a door inside of body. When using side door take care not to foul the claw.
[circled] 4 [/circled] [underlined]Magazine [/underlined] is just a spool carried with 4 toothed sprocket to work footage indicator and a grooved pressure pad behind the gate. Feed spool is lightly friction loaded and

[page break]

in G.45B the receive spool holder has spring device to check reversal.
[circled] 5 [/circled] [underlined] Motor [/underlined] passes 16 frames per sec. at about 5.YOO R.P.M. G.45B is adjusted to 20 frames per sec. [one indecipherable word/symbol] repairs to be made.
[circled] 6 [/circled] [underlined] Claw Unit [/underlined] for drawing film over the exposure aperture and is driven by the large intermediate gear through a small pinion carrying on it’s shaft a cam and an eccentric pin. The pin works in a slot in the lever on which is mounted a spring loaded claw, as this claw moves down it draws the film with it and on it’s return upwards is forced by it’s shape, out of the perforation of the film which is kept still during the operation by the register pin held in engagement with the next hole but one by the action of the cam
[circled] 7 [/circled] [underlined] The shutter unit [/underlined] is a sector shutter

[page break]

driven by a pinion and helical gears from the intermediate gears. Has a normal open sector of 45° for “cloudy” and a reduced aperture of 13½° for “sunny” . Sector is reduced by a solenoid which causes magnetic & frictional drag to be exerted on the auxillary [sic] shutter blade against the pull of a coiled spring so that the auxillary [sic] shutter is [one indecipherable word] until the pin on it reachs [sic] the end of a slot in the main shutter and both turn [one indecipherable word]
[circled] 8 [/circled] [underlined Electrical wiring [/underlined] can be removed as a unit, all connections to other parts being made by plugs or contacts. This unit carries the thermostat control which operates at 65°F + 5°. Adjusts by small grub screw in front of body after removal of the lens unit.
[circled] 9 [/circled] [underlined] The intermediate gears [/underlined] are:- large motor gear, driven by armature pinion of the motor and having frictionally

[page break]

Connected to it is a small pinion. A large rewind gear with friction driven core[?] to magazine. A small intermediate pinion and a large intermediate gear driving the claw & shutter.
[circled] 10 [/circled] [underlined] Motor Speed Test [/underlined]. Load with waste film mark film with pencil at top edge of magazine aperture – run for 10 secs mark again, repeat several times. Amount of film passed in 10 secs to give 16 frames per sec is 4 ft + 3”. G45B will be 5ft + 6”. Depress plunger of release solenoid when not in use – this released spring tension.
[underlined] Maintenance – Sect II – 1Y49 Chap. 10 Para 103-114
[underlined] Footage Indicator [/underlined] includes the –“sunny-cloudy” switch. Footage is operated by a solenoid which draws down one

[page break]

end of a spring-loaded pivotted[sic] lever the rising end of the lever lifts a lightly sprung pawl resting on a toothed wheel. When the circuit is broken the pawl returns and moves the wheel round one tooth. Another pawl prevents the toothed wheel from returning backwards. Friction loaded pointer for zero setting. Adjustment for one tooth movement by screwed stop and/or solenoid position.
[underlined] Titling [?]Unit [/underlined] is operated by clock-work and is fully wound by six turns of the handle. When releases this exposes about 9” of film which photographs the title and details of the pictures previously written in black pencil on the ground side of a cellon tablet, this is placed in the slot on the front of the lens a second slot can be used to insert a clean cellon tablet for

[page break]

varying the lighting intensity for varying the exposure. Speed control is by a pre-set mechanical governor. Camera arrangements similar to G.45. Maintenance similar to camera. Repairs on squadrons only very minor. Replacements nil
[underlined] [one indecipherable word] Unit or Harmonyed [?] must be treated with care and will then need little attention. Do not breathe upon or finger the stainless steel mirror [one indecipherable word] clothe[sic] or camel hair brush only to be used for cleaning. Do not carry the unit loose in the pocket or leave lying about – use the box
[underlined] Type 29 Mounting. [/underlined] This is used with type 32 adaptor plate and provides a free gun mounting in the shape of a dummy gun and is designed from the Vickers “K” Gun. It incorporates all the external wiring circuits including footage indicator Type 44. Dummy barrels carry ordinary bead[?]

[page break]

and ring sights which are adjustable for harmonization and a socket is provided for a reflector gun-sight. Camera secures by type 32 adaptor. Footage indicator works similarly to type 45, plugs into mounting and is a replaceable unit. Electrical circuits are the same as for a fixed camera gun, except that push-button firing switch is replaced by two micro-switches in series with each other and operated by the cocking handle and trigger.
[underlined] Action. [/underlined] On drawing back cocking handle a spring loaded sear secures it and a friction loaded sleeve presses back the locking spring. When cocking handle released [inserted] new[?] [/inserted] spring of front switch contact breaks. When pressing back sleeve [one indecipherable word] releases button and makes contact in rear[?] switch. When trigger is pressed sear is rocked

[page break]

cocking handle returns forward under tension of long return spring running round a pulley [?], sleeve does not move from it’s position because the locking spring is held by a locking plate on the heel of the sear lever, when cocking handle reaches the end of its travel it depresses leaf spring of front micro-switch and makes contact, both switches are now made and camera runs so long as trigger is depressed. A rubber pad and a steel collar makes a shock absorber for cocking handle return. When trigger is released sear is rocked in opposite direction under its spring tension so that the locking plate on the heel releases the locking spring, which pushes the sleeve forward so pressing up the stud so breaking the circuit, camera stops. In this movement the locking spring [one indecipherable word] over the top of

[page break]

the locking plate and prevents the trigger being pressed again until the cocking handle is re-set
[underlined] Maintenance ]/underlined] Sect 3. Chap 2 Para 49-51

[page break]

[blank page

[page break]

[Coloured drawing of an animal holding a stick with caption “The Camera Gremlin” and a signature]

Collection

Citation

George Bubb, “Camera course notebook,” IBCC Digital Archive, accessed March 20, 2019, https://ibccdigitalarchive.lincoln.ac.uk/omeka/collections/document/1078.

Item Relations

This item has no relations.

Can you help improve this description?