How loud is firing the Vickers?

It’s always intrigued me as to how noisy it is to fire the Vickers.  It’s been my view that’s it’s a ‘quiet’ gun for the No. 1 to fire as the cartridge is being initiated almost a metre away from their head.

This has a practical purpose as well, with the Association now able to do function and firing demonstrations for visits to the collection. Not only are there legal requirements about noise exposure, there’s the underlying need to ensure that we protect our hearing. To avoid disturbing our neighbours, the small-scale testing and firing demonstrations are done inside the collection building with all of the doors closed.

Using an application downloaded on my iPhone – so not scientifically accurate but a reasonable indication – I recorded the sound levels while firing.

On the first occasion, I had the phone 2 metres to the front right of the gun at around 1.5 metres off the ground and the other side of a jeep.  This meant that the sound waves were deflected slightly. The maximum sound level was 105 decibels.

On the second occasion, the phone was on my lap in the No. 1 position. It’s worth noting that I was sat on a stool so the phone was actually at the head height of a No. 1 sat on the floor. This recorded only 102 decibels so slightly quieter in this position.

Both of these levels are below the peak sound pressure limit value of 140db and can be easily reduced below the exposure action limit value of 80db for daily or weekly limits if exposed repeatedly. Using standard commercial ear defenders, that the Association has bought for visitors, does this instantly.

I have to consider the variation in production of the PPU blank so I will continue to do these recordings whenever possible and keep the information up to date on this blog. I’d also like to engage a noise professional who can do multiple readings from different places around the gun. This would require an extended piece of firing so this could be a funded piece of research, possibly suited to a student project for an environmental health degree – please contact us if that’s something you could facilitate in any way. It’ll also be good to research it when firing live.

The video below shows one of the firing events from the second occasion when I was recording. From the difference in muzzle blast, it’s possible to see some of the variation in blank as the different amount of gases expended will relate to the noise.


During British Service

From a historical perspective, the British Army has had concerns over the hearing of its troops but I’ve not been able to find any related to machine gunners.

In 1944, Army Council Instructions 732 (June) and 1420 (October) were issued. The October amendment reads:

The discharge of weapons may, in certain circumstances, cause considerable damage to the ears of personnel serving in:-

  • Gun detachments of Field, Medium and Heavy Artillery,
  • Gun detachments of Light A.A., Heavy A.A. and Coast Artillery units,
  • Gun detachments of R.A. and Infantry Anti-Tank units,
  • Infantry Squads for Protectors, Infantry Anti-Tank and Mortars,

when not wearing some form of ear protection.

It is important, therefore, that personnel whose duties take them close to these guns firing protect their ears by plugs of cotton wool.

The 1943 (provisional) manual for the PIAT actually identifies using pieces of flannelette as well as cotton wool.

There were ear protectors issued to civilians with their respirators at the start of the Second World War and it’s possible that these were formally issued later on.

There’s no mention of ear protection for machine gunners but the problem certainly existed and many machine gunners, those who used the Vickers and those since, will have experienced hearing damage from small arms firing – certainly many of the Small Arms School Corps Comrades I have met wear their hearing aids where they didn’t wear their ear protectors.


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How much does a Vickers weigh?

This article isn’t an extension of my previous blog article about light, medium and heavy machine guns, although it’s something I could rant about quite a bit.

When doing an annual ‘spring clean’ of the Vickers collection this month, we had to get all of the guns off of their tripods and give them a once-over.  During this, I noticed that one of the guns felt significantly heavier than the others. It was a Mark I gun that had been converted from a Mark XXI when the Australians no longer required them in their armoured vehicles. It was a 1945 gun so one of the last few made and I thought it would be interesting to compare it with one of the earliest guns in the collection – L 1053 from May 1915.

This immediately showed a difference of 2.7 kg which equates to an increase of 20% over the 30 years of manufacture. Quite remarkable. It made me think what the differences would be on some of the other examples in the collection.

L 1053

An early Vickers Mark I manufactured at Erith in May 1915. It is extensive lightened and features some of the earliest manufacturing techniques. They include the ‘five-arch’ top cover and side plates with extensive machining. This was very labour intensive and the machining reduces over the period of the Great War as production speeds had to increase to ensure that the needs of the army could be met regarding the numbers of machine guns in service. It was also made with the earliest type of fluted water-jacket.

Weight: 13.68 kg.

One of the most noticeable accessories affecting the man-carry of the gun was the Sangster Auxiliary Mounting. It meant the gun could be used without the Mark IV tripod in an emergency. It was left on the gun for the majority of the time as it wasn’t easily removed.

Weight: 17.21 kg (including Sangster Mount).

B 2296

An Australian-made Vickers originally built as a Mark XXI but then converted, in 1945, to a standard Mark I. This meant that the original features of the Mark XXI, which included different filler plugs at the rear of the water-jacket and the pistol grip removed and replaced with a cross-piece. All the guns of this period feature the dial sight bracket as part of the standard equipment.

All of the Australian guns were made with very simply produced components that allowed for mass production. They were made with the smooth water-jacket.

Weight: 16.36 kg.

1186

Another Australian-made gun but this one was a Mark I made in 1939/40. Other than conversation elements from the Mark XXI, it is the same as B 2296.

At the time of weighing, it was fitted with the water-jacket cover and the flash eliminator.

Weight: 17.53 kg (including jacket cover and flash eliminator).

H 5113

This example in the collection was built at the end of the Great War, in 1918, as is one of the early examples of a ‘smooth’ water-jacket. It isn’t, in fact, smooth as some excess weight was machined from the water-jacket, presumably by lathe.

All other components are, visually, the same as later examples and the early machined components are not used at all.

Despite being a Great War Mark I gun, it is fitted with accessories as used in the Second World War. It is used as such for displays with the VMGCRA.

Weight: 16.65 kg (including jacket cover and flash eliminator).

V 6750

The example of a Mark I gun was made at Vickers-Armstrongs in Crayford. It was made in 1943/44 and is quite crudely finished compared to the other examples shown here.

It has undergone some repairs to the crosspiece as it’s believed that this example was in use with airborne forces and has been parachuted from an aircraft.

It is fitted with the water-jacket cover and flash eliminator.

Weight: 17.08 kg (including jacket cover and flash eliminator).

Summary

The variations in weight are affected by the accessories but, given the fact that similar accessories are in use on several of the examples, it doesn’t have a significant influence.

Another factor to consider is that all of these examples are deactivated and this involves some metal being removed and some being added. There may be some variations because of the different people carrying out the deactivation work but unlikely to be significant.

And of course, none of these are filled with any water so that has to be added when considering the weights that the machine gunners had to carry – in this case the No. 2 of the machine gun team.

The table below is a summary of the differences between the different guns, sorted by date of manufacture from left to right and top to bottom.

Fullscreen capture 04032019 211451

Whilst B 2296 is shown as lightest of the smooth water-jacket examples, it’s possible that this was distorted by the lack of water-jacket cover and flash eliminator.

It’s worth adding that the 1914 handbook for the Vickers gives the empty weight as 28 1/2 lb (12.9 kg) so 0.8 kg from the tested weight. It’s more interesting that the 1945 data summary for the Canadian Electrical and Mechanical Engineers (armourers) shows that the weight of the gun is 30 lb when empty. This is 13.6 kg in metric weight and clearly reflects the earlier manufactured guns, not the later. It would clearly come as a surprise to the soldiers who then went on to carry the gun into action.


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