A1

A1
Preceded by	EM2 EM3
Succeeded by	A2
Filter connection	40mm DIN
Made in	Argentina
Period	1934-1936
Users	1934
Issued to	Ejército Argentino (Argentinian Army)
Manufacturer	Pirelli Argentina

The A1 was the standard military gas mask for the Argentinian army. It was manufactured by Pirelli Argentina on the base of the EM2 and EM3, taking elements from both.

Mask overview

The facepiece was made of a two-layers orange rubber, textured on the outside while smooth on the inside. The head harness had five straps. The eyepieces were made of three layers, two glass ones and a cellulose one. Inside the mask, there was a sponge layer that helped to reduce the dead space inside the mask and to prevent fogging while wearing it; this sponge-section design was attached directly to the rubber inside. The intake-outtake assembly is connected to the mask at the bottom and it has three holes: a threaded one for the hose, one for the connection to the mask and the third was for the exhale valve, kept still by a lid; inside there is an inhale valve. The filter, stored in the bag, was attached to the intake-outtake assembly through a corrugated hose threaded on both ends.

Front view

Left side

Right side

Straps

Inside

intake-outtake assembly opened

Exhale valve and its cover from the inside

Thread

Left side marking. This sample is a size "M", which stands for medium in Spanish

Right side marking. This sample is marked 1934 with serial number 857

Filter

The filter was an adaptation of the Tubin pattern industrial filter that had a thread on the top. It has two holes at the bottom to let air in.

The filter. Note the thread and the "Pirelli Argentina" logo

Bottom of the filter. If you were to use the filter, you'd have to open both

Markings. The serial number 857 is almost completely faded but 1934 is clearly visible

Kit

The mask came with its hose and filter inside a square bag, which had a section for the filter and another for the mask when not in use. Two small pockets on the inside stored a spare exhale valve in a box and the anti-fogging lenses.

The full kit

Full kit, with hose and filter attached

Double threaded hose. Note that this sample lacks gaskets

Inlet thread on the hose

Anti-fogging lenses. Note the instructions in Spanish

Spare exhale valve and its box. The first has the Pirelli star symbol

The bag

Bottom of the bag

Inside of the bag. Note the two pouches on the inside

History

Origin and adoption

An A1 intake on the left and an EM2 intake on the right. Note that the A1 one is positioned backwards and has a thread, while the other doesn't

The A1 was adopted in 1934 as the first Pirelli military mask for Argentina. Its bases were the EM2 and the EM3, it had the fixed straps of the first and the larger eyepieces of the second.

There were some more characteristics designed specifically for this mask:

• the exhale valve pointed backwards (probably to reduce the bulk and to avoid having it bumping on things)

• the intake, the filter and the hose were given threads (probably as an emergency measure to be able to use the filter even if the hose was thorn)
  

  A1 masks in use

  

  A1 (on the right) from the Museo de Armas de la Nacion (Buenos Aires)

Possible issues for abandoning of the A1

The A1 had a very short lifespan in comparison to other military masks, as in only 2 years it was replaced by the A2; in fact, there are not many pictures of these in use. This might have been due to a number of possible reasons:

• The large machined piece at the front probably was still too bulky, regardless of the measure taken

• The soft rubber made the intake-outtake assembly wobble too much, restraining airflow and encumbering respiration (same issue as the Penna)

• The pressure required to exhale might have been deemed too much (a problem that was fixed by the double exhale valve of the A2)
• The seal might have been not secure enough (another problem solved with the A2 with the addition of two extra straps)
• The mask overall might have been too expensive to make