Op Mudlark - FV437 Pathfinder, FV432, FMC M113-1/2 (Lynx) , M551 Sheridan

[Mark Ellis]

Just to put the cat amongst the Pigeons.

FV421 and FV431 - and an SP FV434

FV421 with registration 00 CA 24 and 00 CA 29

FV431 with registration 06 EB 03, and P1, and 06 EB 01 marked as W1

FV434  01SP12

 

FV421

There is no 00 CA 2X in MERLIN, so cast before 1st January 1984.

FV431

FV434 SP

 

[Tarland]

3 hours ago, wally dugan said:

After a bit more digging l would like to add the following P1 was number W4 and numbered 06 EB 04 and was transferred to SEME  on the 27/7/68 P2 was number W3 and  renumbered  06 EB 03 and transferred to RMSC  SHRIVENAM on the 8/9/69  W2 06 EB 02 was first sent to the RAC CENTRE BOVINGTON on the 6/4/67 and transferred to REME APPRENTICE SCHOOL ARBORFIELD on the 3/12 71 last         06 EB 01 was sent to 10  AVD date not published  It would appear that more FV 421 were built  than FV 437 There is a lot more to the story of the FV 400 series than you may first think and it began as early as 1950

Wally, thanks for this. What is 10 AVD?

[wally dugan]

Not really l have the lists of theFV401 FV420 FV421 that were at FVRDE/MEXE as l said there is more to the story than just a few pictures 10 AVD ARMOURED VEHICLE DEPOT  l will look if l have it's location

Edited December 30, 2023 by wally dugan

[fv1609]

A nice little find of a few years ago.

 

[fv1609]

Another one that didn't make it.

[Mark Ellis]

30 minutes ago, fv1609 said:

Another one that didn't make it.

Is that the 402, Clive?

This is the 421 off the video

[wally dugan]

FV 421 were numbered  from 00 CA 22 TO OO CA 31 with the exception of 00 CA 29 WHICH was a FV423  and was scrapped in 6/4/65

[fv1609]

1 hour ago, Mark Ellis said:

Is that the 402, Clive?

This is the private venture put forward by FMC as the Command & Reconnaissance Vehicle to tempt the US Army who chose M114 instead. It was trialled by FVRDE on 11th June - 14th July 1964.

Swimming trials were at FVRDE site Horsea Island 29-30 June 1964

[Mark Ellis]

1 hour ago, wally dugan said:

FV 421 were numbered  from 00 CA 22 TO OO CA 31 with the exception of 00 CA 29 WHICH was a FV423  and was scrapped in 6/4/65

Thanks, @wally dugan 

So this is a 423 Command vehicle then

[Mark Ellis]

28 minutes ago, fv1609 said:

This is the private venture put forward by FMC as the Command & Reconnaissance Vehicle to tempt the US Army who chose M114 instead. It was trialled by FVRDE on 11th June - 14th July 1964.

Swimming trials were at FVRDE site Horsea Island 29-30 June 1964

Isn't that the M113 1/2, that's in the Mudlark film? 

[fv1609]

7 minutes ago, Mark Ellis said:

Isn't that the M113 1/2, that's in the Mudlark film? 

No idea, haven't seen the film. The report refers to it as "FMC Command & Reconnaissance Vehicle (FMC C. & R.) uses many parts common with those of M.113" 

One prototype was doing the rounds of several European countries & FVRDE were allowed to have it for a month.

[wally dugan]

that is what it says 00 CA 29 all on that list seem to have ended up as targets

[Mark Ellis]

3 minutes ago, wally dugan said:

that is what it says 00 CA 29 all on that list seem to have ended up as targets

It certainly explains the canvas either side of the vehicle 🙂 

[Tarland]

1 hour ago, Mark Ellis said:

Isn't that the M113 1/2, that's in the Mudlark film? 

Yes it is the 113-1/2

[10FM68]

And the M113 1/2 is registered 50BT05 in Aug - Oct 1966 so, presumably, was with FVRDE long enough to be registered and under trials 2 years later than the Horsea Island tests of June 64.

[Tarland]

23 minutes ago, Tarland said:

Yes it is the 113-1/2

Bovington video on their Canadian Lynx

[fv1609]

FMC

 

[fv1609]

That was a good video although it didn't have time to mention some criticisms from the FVRDE report.

1. Vibrations from 6 inch pitch track link and the engine and track noises were high.

2. Only one external fire handle on the left hand side of vehicle & no portable small extinguishers on the outside.

3. Excellent vision through periscopes was nullified by absence of any wipers.

4. Servicing of wheel hubs was difficult. The filler caps were hard to remove & oil hole was very small.

5. There was no ventilation equipment.

A general criticism of the vehicle concept was that for the number of crew (3) & the armament, the vehicle was larger & heavier than it need be.

The propulsive efficiency of the FV430 is substantially better than the FMC. Although the FV430 was considerably inferior to FMC & M113 when going astern taking some time to pick up way & very limited manoeuvrability.

The field of the IR night vision was 26 degrees the British requirement was 40 degrees minimum was 'essential' but 55 degrees was 'desirable'. The field of IR illumination was downgraded by 20% due to the illumination from 100W bulbs to overcome this 240W would be required.

Radio interference 30-60 Mc/s averaged 35 dB above 1 microvolt that exceeded the acceptable level of 8 dB.

26th October 1965

 

[Tarland]

20 hours ago, fv1609 said:

That was a good video although it didn't have time to mention some criticisms from the FVRDE report.

1. Vibrations from 6 inch pitch track link and the engine and track noises were high.

2. Only one external fire handle on the left hand side of vehicle & no portable small extinguishers on the outside.

3. Excellent vision through periscopes was nullified by absence of any wipers.

4. Servicing of wheel hubs was difficult. The filler caps were hard to remove & oil hole was very small.

5. There was no ventilation equipment.

A general criticism of the vehicle concept was that for the number of crew (3) & the armament, the vehicle was larger & heavier than it need be.

The propulsive efficiency of the FV430 is substantially better than the FMC. Although the FV430 was considerably inferior to FMC & M113 when going astern taking some time to pick up way & very limited manoeuvrability.

The field of the IR night vision was 26 degrees the British requirement was 40 degrees minimum was 'essential' but 55 degrees was 'desirable'. The field of IR illumination was downgraded by 20% due to the illumination from 100W bulbs to overcome this 240W would be required.

Radio interference 30-60 Mc/s averaged 35 dB above 1 microvolt that exceeded the acceptable level of 8 dB.

26th October 1965

 

Clive, thanks for this. Whats the title/document number of this report?

Is the FVDRE wading photo above from the report??

Obviously the author of the report had a liking for the Ferret when it came down to the size. I'll have to go and see how the CVRT compares size wise

[fv1609]

Yes that & the line drawings came from FVRDE Report No. FT 2256

It is an awkward publication to handle it measures 13.5" x 8" contains many full size photographic pages which are glossy and slightly curled that make it difficult to photo without glinting. It is all tightly stapled together making holding pages open difficult especially if trying to take a photo. Sadly some of the photos have faded badly although they could be enhanced by increasing the contrast with some photo editing. 

You will see that on the first page the dates are given for 1965, yet on the next page it reiterates the dates of trial but states 1964.

It is quite a detailed report on many aspects of the vehicle not just water performance compared with FV432 & M113 but the fields of vision for commander, driver & co-driver in daylight & IR.

I bought it from the Tank Museum many years ago, whether they had lost interest in it or have a better copy I don't know.

[10FM68]

I've just had a look at the Profile Publications No 53 dated Jan 73.  The photos there show the derelict FV421 at Lulworth - so it was already derelict by then.  Some of the other photos Wally posted above are also there.  An early FV434 (W5) is shown as 06EB00. FV434 (P2) is shown with civilian VRM 521FUW.  Clearly, 06EB01 was given to at least two different vehicles the FV431 above and the FV437 in Thailand - which seems odd, but suggests that the 06EB-- batch was FV430 generally for prototypes.  Unfortunately, there is little information in the Profile about FV437, merely saying that it had a capstan winch which paid out forwards and hydro-jet propulsion.

[ltwtbarmy]

I managed to find this publication online if anyone’s interested. Happy new year everyone!

https://boxartden.com/reference/gallery/index.php/AFV-Profiles/FV-432-Series

[Mark Ellis]

18 minutes ago, ltwtbarmy said:

I managed to find this publication online if anyone’s interested. Happy new year everyone!

https://boxartden.com/reference/gallery/index.php/AFV-Profiles/FV-432-Series

It's amazing that no one mentions the engine being in the middle of the vehicle. 

[andym]

40 minutes ago, Mark Ellis said:

It's amazing that no one mentions the engine being in the middle of the vehicle. 

Are we absolutely sure that was the case, Mark?  Some drawings or interior photos would be really helpful.

Andy

[David Herbert]

Yes we are sure that the FV437 has its engine in the middle. It was mentioned in the commentary of the Mudlark film. Also it was mentioned in the film that there is permanent wading trunking around the engine grills so that there is no need to erect a flotation screen as with a FV432. This has disappeared from the last remaining one on outside display.

Note also that the FV437 has different road wheel spacing to a FV432. This is shared with the FV431 load carrier and I am satisfied that 06EB01 was originally built as a FV431 and then rebuilt into the FV437 used in Mudlark. This type of rebuild was also done to produce the prototype Green Archer vehicle which was converted from a FV432 trials vehicle and retained the same registration despite being given a new FV number.

Prototype vehicles were given P numbers and usually civilian type registration numbers. They often differed significantly from each other (there was a 432 prototype with only four road wheels each side for example). Once the basic design was established vehicles would be ordered for trials and given W numbers and army registration numbers. These started life identical but were modified as improvements were thought of so varied a lot as time went on.

There are for example pictures of FV421 00CA24 with its original continuously sloped front and also the revised front with the more vertical windscreens. There were many different transmissions tried in the VF421s including the fully auto Allison 6 speed box that went on to be used in the FV430 series. The last remaining FV421 has the Allison box and the steering box that went into the prototype FV432s. Also the revised idler mountings (idler moved backwards and stronger adjuster) and different rear air trunking. This one is 00CA25. Does anyone have a photo of it in service ? I have never found one.

David