WWll Bomb Releases

[Djbeffects]

Hi Everyone I'm new here this is my first post so excuse me if I've not posted in the correct format.
I have recently purchased several small bomb release catches.
Not sure if they come under Avionics as they are electrically triggered?
I'm trying to get them working from 28v DC power source but am not having much luck. I have a horrid feeling they may be AC.
Is there anyone out there with more knowledge on these?
If they are AC can they be converted to DC?
Any help would be much appreciated.
Regards
Dominic

 

[Crimea_River]

Welcome aboard. Sorry I can't help you but hopefully someone should be along shortly.

 

[Crimea_River]

Maybe in the meantime you can expand a bit on the type of aircraft these were used on. I can see that it's probably a British unit from the number but the timeframe may be important. I have a little bit of knowledge of late war Mosquitoes and I believe their systems ran on 24V DC.

 

[Djbeffects]

Maybe in the meantime you can expand a bit on the type of aircraft these were used on. I can see that it's probably a British unit from the number but the timeframe may be important. I have a little bit of knowledge of late war Mosquitoes and I believe their systems ran on 24V DC.

Thanks for your response. Yes I believe British and 1940's but I know little else.
There are others that are simular to these on the Canberra type aircraft.
I don't actually know which specific aircraft these come from. I have tested at 24VDC and 28VDC with no luck. It could be that the insulation on the coils is damaged after years of storage?.

 

[Wurger]

Just use the ohmmeter. If it indicates a quite low resistance it means that there is a short circuit. If it is 0 it means no current flow. You may use a multimetr with the function Buzzer that can help with that.

 

[Djbeffects]

Just use the ohmmeter. If it indicates a quite low resistance it means that there is a short circuit. If it is 0 it means no current flow. You may use a multimetr with the function Buzzer that can help with that.

Great yes I hadn't thought of that I will try latter and see how I get on.
Many thanks
Dominic

 

[Graeme]

Very different in shape - but this is the British small bombs container (1943) with three bomb release units. The 'jaws' hold the drop bar.
From what I understand (which is usually little) they're operated by 24 volts DC.

 

[Djbeffects]

Very different in shape - but this is the British small bombs container (1943) with three bomb release units. The 'jaws' hold the drop bar.
From what I understand (which is usually little) they're operated by 24 volts DC.

View attachment 626543

Great interesting. The more I hear about it these were most likely 24V DV and the coils have degraded apparently a common problem even at the time let alone 70yrs latter! Many thanks

 

[Crimea_River]

You may want to see if you can get a full copy of Air Publication AP 1664 from Kew. https://www.nationalarchives.gov.uk/

I have a partial copy that covers only single hook type. Maybe a full copy will have the one you are wrestling with. Good luck.

 

[Djbeffects]

You may want to see if you can get a full copy of Air Publication AP 1664 from Kew. https://www.nationalarchives.gov.uk/

I have a partial copy that covers only single hook type. Maybe a full copy will have the one you are wrestling with. Good luck.

Useful information thank you I will look into this.
Many thanks
Dominic

 

[MiTasol]

Many of the RAF units were 12v DC and as far as I know there were no RAF AC Release units in WW2. Certainly the Lincoln was still all DC on that subject.
The attached file predates what you are looking at but may be of interest. Sorry about the watermark but I do not want unscrupulous web sites selling copies of a document I provide FOC.
My copy of AP 1664 also only covers a small number of units and not that one
The RAF used some weird voltages in AC so, if AC you will need to know what voltage and frequency. There are plenty of online sites covering making AC power sources that run from mains or battery.

 

[Djbeffects]

Many of the RAF units were 12v DC and as far as I know there were no RAF AC Release units in WW2. Certainly the Lincoln was still all DC on that subject.
The attached file predates what you are looking at but may be of interest. Sorry about the watermark but I do not want unscrupulous web sites selling copies of a document I provide FOC.
My copy of AP 1664 also only covers a small number of units and not that one
The RAF used some weird voltages in AC so, if AC you will need to know what voltage and frequency. There are plenty of online sites covering making AC power sources that run from mains or battery.

Very interesting thanks for your reply and document.
I will go though it and see if I glean some Information.
Many thanks
Dominic

 

[PETERTHEEATER]

They are not WW2. The No 1 Electro Magnetic Release Unit (EMRU) was used in the Avro Triple Bomb Carrier of the Canberra aircraft and in the Valiant 5 Store and and Victor and Vulcan 7 Store. bomb carriers. A single unit was used also in the Victor bomber tail drag parachute to operate the parachute doors. The unit IS 24 volt DC supply actuated but in service use the supply from the aircraft was 'pulsed' to avoid 'stiction' nevertheless it should actuate with a straight 24 volts DC

During my RAF life I used to service these. On the left side of the case (face up) are two copper contacts. Try applying 24 VDC to ONE contact at a time with the other probe on the case (earth). You have, probably, found the manual release plunger on the top corner. Depressing this should open the jaws. When open, use thumb and forefinger to close and lock them then manually release. Do this several times to loosen up the internal gunge. Have you opened the case yet? If you want to, ask and I will give you some tips.

 

[Djbeffects]

They are not WW2. The No 1 Electro Magnetic Release Unit (EMRU) was used in the Avro Triple Bomb Carrier of the Canberra aircraft and in the Valiant 5 Store and and Victor and Vulcan 7 Store. bomb carriers. A single unit was used also in the Victor bomber tail drag parachute to operate the parachute doors. The unit IS 24 volt DC supply actuated but in service use the supply from the aircraft was 'pulsed' to avoid 'stiction' nevertheless it should actuate with a straight 24 volts DC

During my RAF life I used to service these. On the left side of the case (face up) are two copper contacts. Try applying 24 VDC to ONE contact at a time with the other probe on the case (earth). You have, probably, found the manual release plunger on the top corner. Depressing this should open the jaws. When open, use thumb and forefinger to close and lock them then manually release. Do this several times to loosen up the internal gunge. Have you opened the case yet? If you want to, ask and I will give you some tips.

Thank you so much for this detailed reply.
Yes I can get the manual push button to operate the jaws and they reset as you describe. I will try touching the positive on the copper atrips as you have mentioned.
I'd be interested in any pointers you can give for servicing, what to look for etc.
Thank you so much.
Regards.
Dominic

 

[PETERTHEEATER]

Thank you so much for this detailed reply.
Yes I can get the manual push button to operate the jaws and they reset as you describe. I will try touching the positive on the copper atrips as you have mentioned.
I'd be interested in any pointers you can give for servicing, what to look for etc.
Thank you so much.
Regards.
Dominic

One of the two contacts on the side is the RELEASE and the other is COCKING. The latter is open circuit when the jaws are open and with the jaws closed and locked completes a circuit to earth. When installed a test box connected to the carrier would show green lights for those EMRUs that were correctly closed and locked. The test box injected only about 4.5 VDC. If you inject an uncontrolled 24VDC to the 'Cocking contact' with the jaws closed it will be a dead short.

 

[Djbeffects]

One of the two contacts on the side is the RELEASE and the other is COCKING. The latter is open circuit when the jaws are open and with the jaws closed and locked completes a circuit to earth. When installed a test box connected to the carrier would show green lights for those EMRUs that were correctly closed and locked. The test box injected only about 4.5 VDC. If you inject an uncontrolled 24VDC to the 'Cocking contact' with the jaws closed it will be a dead short.

Thanks again all very useful information!
Do you know what loads (weight) these were tested to carry?
Many thanks
Dominic

 

[PETERTHEEATER]

Thanks again all very useful information!
Do you know what loads (weight) these were tested to carry?
Many thanks
Dominic

Yes, they were rated for a 1000 pound HE Bomb which was for Canberra and the three V-Bombers the standard conventional bomb, 6 x 1000 for Canberra, 21 x 1000 for Valiant, 35 x 1000 for Victor and (I think) 21 x 1000 for Vulcan. As a young Armament Fitter I worked Canberra/Victor/Valiant. Because the Victor tail brake parachute installation used the No 3 EMRU (big brother to the No 1) to hold the chute shackle and the No 1 EMRU to operate the doorsthe task of fitting the brake chute fell onto the 'plumbers' (Armourers)

 

[Djbeffects]

Yes, they were rated for a 1000 pound HE Bomb which was for Canberra and the three V-Bombers the standard conventional bomb, 6 x 1000 for Canberra, 21 x 1000 for Valiant, 35 x 1000 for Victor and (I think) 21 x 1000 for Vulcan. As a young Armament Fitter I worked Canberra/Victor/Valiant. Because the Victor tail brake parachute installation used the No 3 EMRU (big brother to the No 1) to hold the chute shackle and the No 1 EMRU to operate the doorsthe task of fitting the brake chute fell onto the 'plumbers' (Armourers)

 

[Djbeffects]

Great thanks again great information here.
Thank you!
Dominic

 

[PETERTHEEATER]

From your Avatar you favour Canberaa? The Bomb Carrier for this was the Avro Triple which could carry two or three bombs. Each built in Release Housing used 1 x EMRU No 1