British Army News and Discussion

[Big_Zucchini]

Regarding the noise point, I can't comment on other countries but hasn't it been quite normal for personnel in British armoured vehicles to need to wear headphones with mics due to the noise from the engines? Testing hearing would make sense to make sure they were working properly. The point of concern would be if the headphones weren't effective. The article is silent on that.

On the rest, I guess either those are issues that have been resolved or will need to be before the vehicle can be accepted.

Even cheap headphones can attenuate noise at around 30dB. That's gonna block 99.9% of the noise. The article makes it fairly clear they are a solution, but a temporary one.
Sound noise has the same mechanucal properties as other forms of noise such as material vibrations. And the article also makes it clear there are excessive vibrations from the engine, felt across the vehicle.
The fix could be relatively easy. The source cannot be touched, but the vibrations can be attenuated. Fix the vibrations and you also fix much of the noise.
As this could mean reshaping of some components, this may entail recertification of either components, or in the absolute worst case, the whole vehicle. So basically bureaucracy.

 

[Terran]

30Db is equal to a quiet rural area. 44Db is most bird calls. passenger car is 70 db. Motorcycle is 100 db. An M2 Bradley very but levels from 100-130db. So I would like to know the noise level here and how it differs from other armored vehicles.

 

[StobieWan]

Exactly - only been in the back of one UK AFV and that was
"This is LOUD"
"WHAT?"
"I SAID THIS IS LOUD"
"I CAN'T HEAR YOU, IT'S TOO LOUD IN HERE"


What were the targets and have they been measured objectively ?

 

[oldsig127]

Exactly - only been in the back of one UK AFV and that was
"This is LOUD"
"WHAT?"
"I SAID THIS IS LOUD"
"I CAN'T HEAR YOU, IT'S TOO LOUD IN HERE"


What were the targets and have they been measured objectively ?

To be fair, that also applied in the back of an M-113 fifty years ago and still does.

oldsig

 

[ngatimozart]

To be fair, that also applied in the back of an M-113 fifty years ago and still does.

oldsig

Yep, but you know the poms and how much they love sticking to tradition, so even if their new IFV was quiet they'd install microphones, amplifiers and speakers

 

[Redlands18]

Yep, but you know the poms and how much they love sticking to tradition, so even if their new IFV was quiet they'd install microphones, amplifiers and speakers

As long as it has the Tea Kettle, they’ll be fine

 

[ngatimozart]

As long as it has the Tea Kettle, they’ll be fine

The boiling vessel is a compulsory component to be installed in every pommy fighting vehicle. I would presume that the same would apply to Aussie and Kiwi ones as well.

 

[Terran]

The boiling vessel is a compulsory component to be installed in every pommy fighting vehicle. I would presume that the same would apply to Aussie and Kiwi ones as well.

Also used in American surprisingly.

 

[oldsig127]

The boiling vessel is a compulsory component to be installed in every pommy fighting vehicle. I would presume that the same would apply to Aussie and Kiwi ones as well.

No. That would be the fridge. As seen in the bustle rack of our Abram's. It's alright for Kiwis and Poms in climates that'll freeze their L&P or pink gins, but proper cold beer is a necessity of life north of the Tweed and south of the TSI

oldsig

 

[Big_Zucchini]

30Db is equal to a quiet rural area. 44Db is most bird calls. passenger car is 70 db. Motorcycle is 100 db. An M2 Bradley very but levels from 100-130db. So I would like to know the noise level here and how it differs from other armored vehicles.

I was talking attenuation of sound, not absolute sound pressure levels.
That is, a simple set of cheap headphones will attenuate, if your examples are correct, a sound from motorcycle level to passenger car level.

 

[StobieWan]

To be fair, that also applied in the back of an M-113 fifty years ago and still does.

oldsig

Exactly -they're all just tin boxes with unmuffled engines so I'd be curious as to more details on how the Ajax fails on that detail.


Not encouraging for sure however.

 

[StobieWan]

Yep, but you know the poms and how much they love sticking to tradition, so even if their new IFV was quiet they'd install microphones, amplifiers and speakers

Nah, we'd just specify an APU for "silent watch" and end up bringing in something older than the ark from the scrap yard and have troops listen to this thumping two stroker pounding along

 

[Terran]

I was talking attenuation of sound, not absolute sound pressure levels.
That is, a simple set of cheap headphones will attenuate, if your examples are correct, a sound from motorcycle level to passenger car level.

my sources on sound levels Comparative Examples of Noise Levels - IAC Acoustics

Custom Protect Ear

ProtectEar

www.protectear.com

https://www.sto.nato.int/publications/STO%20Meeting%20Proceedings/RTO-MP-AVT-110/MP-AVT-110-$KN1.pdf

However reread my post as I don’t think I quoted you specifically. I was mostly providing examples of sound levels as a base of comparison then basically asking, “What is the sound level in the Ajax. How does it differ from other NATO vehicles of similar types.”
The Suns Story reported that Personal had to wear Noise Canceling headphones. That’s the norm for military operations anyway. It’s hard to think of a military vehicle that doesn’t produce over 80DB. Outside of a Civilian vehicle that was painted in Army Colors. Even Humvee can crank out 100DBs . The British Army already issues active noise canceling headphones. RA180 Crewgard | Racal Acoustics
Yet it seemed to imply that this vehicle was extraordinarily noisy. Which is where my question is.

 

[Big_Zucchini]

https://www.facebook.com/permalink.php?story_fbid=818748009078864&id=250896539197350

Rafael's Trophy has been selected for integration on Challenger 3. The specific version is Trophy MV, which is a lighter variant of the original, with a smaller warhead and more optimized and streamlined build.

Trophy is established as the world's most tested, combat proven, longest serving, and most mature APS on the market.

Since before Trophy was even selected by the IDF, Rafael has been considering the concept of intercepting APFSDS munitions, and at least in 2005 IIRC, a suitable warhead was tested.

However, it seems Rafael now believes the correct approach is to exclude APFSDS from the list for now, and use hybrid protection for this threat.
The IDF envisioned a new iteration of its Merkava tank operational with an anti-KE APFSDS by 2023 (original plan was for 2021), but it may not be fulfilled.

But if and when this technology proves itself, the Challenger is yet another western tank that will get this important capability to keep it ahead of its peers.

 

[Terran]

Interesting that they chose the MV version. Abrams and Merkava IV both I believe use the HV. MV seemed more oriented to Heavy and medium weight IFVs

 

[south]

Ajax going from bad to worse in the UK with real concerns on the project future….

The British Army’s Greek Tragedy

The British Army has spent £3.2 billion on its Ajax family of vehicles, but as major problems beset the programme and its role in the force remains poorly defined, the Army faces a stark choice between doubling down or moving on.

rusi.org

 

[Hone C]

Ajax going from bad to worse in the UK with real concerns on the project future….

The British Army’s Greek Tragedy

The British Army has spent £3.2 billion on its Ajax family of vehicles, but as major problems beset the programme and its role in the force remains poorly defined, the Army faces a stark choice between doubling down or moving on.

rusi.org

Another chapter in the ongoing drama that is British AFV procurement. There was always questions about whether Ajax was the correct platform, especially integrated with Boxer in the Strike Brigades.

More serious than the vehicle faults and procurement issues is the line " the army now finds itself without a coherent warfighting doctrine."

 

[Terran]

Finally some meat on the problem.
Quoting from The British Army’s Greek Tragedy

However, tests on the sound produced by the vehicle demonstrated that it was within useable limits. Subsequent investigation following loss of hearing by crews trialling the platforms has concluded that the issue arises from the integration of the Bowman headsets for the crew radios, which were picking up engine noise, amplifying it as the vehicle accelerated, and putting the sound directly into the crews’ ears.

ah hah! So that’s the sound issue.
Vibrations

excessive vibration is preventing the main armament from stabilising on the move, damaging the electronic systems that make Ajax a step-change in capability and leading to a high rate of component failure, with the idler and rear road wheels sheering off with concerning regularity. Crews meanwhile have suffered from symptoms that could indicate a risk of prolonged use of the platform leading to Hand-Arm Vibration Syndrome.

 

[ngatimozart]

Finally some meat on the problem.
Quoting from The British Army’s Greek Tragedy
ah hah! So that’s the sound issue.
Vibrations

Easily diagnosed, but more difficult to mitigate especially if it's the Poms doing it.

 

[Terran]

Well I was reading stuff that made it sound like the vehicle became some kind of comic book banshee. With words like “Radiation” that made no sense. I mean most armored tracked vehicles are pretty much a rolling metal concert but not instant deafness. This report nails the issues and gives hope they can fix.