Pierce-Arrow Armoured AA Lorry

[David]

An Anti-Aircraft Brigade was formed by the Royal Marine Artillery in the Autumn of 1914 for service in the field. The equipment chosen for this unit consisted of the Vickers Naval 2-pdr. automatic gun - usually known as the “pom pom” - mounted on a Pierce­Arrow 5-ton lorry chassis, armoured.

The establishment fixed for the R.M.A. A.A. Brigade was four batteries, each with four guns, together with supporting transport and a head­quarters. Also included were twenty­four motor-cycle combinations equip­ped with Maxim machine-guns. To ensure that the Brigade was highly mobile, transport was on a generous scale, with thirty-four Pierce-Arrow lorries and two Pierce-Arrow workshop vehicles. Although there were only to be sixteen guns, forty-eight chassis were ordered for them, the balance to be maintained as spares.

The order for the armoured cars (also the Pierce-Arrow lorries and workshops) was placed with Wolseley Motors Ltd., a subsidiary of Vickers, on 30 December 1914. The Pierce­Arrow chassis (imported from the U.S.A.) used was a 14-foot wheelbase type with 30-h.p. four-cylinder engine and shaft transmission to the rear wheels. The wheels were the spoked artillery type with detachable rims and fitted with solid rubber tyres, 36-inch singles at the front and 40-inch twins at the rear. The armour protection was 5-mm. plate on thirty-two vehicles and on the remaining sixteen was increased to 7.5mm with roofs of 5mm plate. In addition to the "pom pom", one Maxim machine-gun was provided, for which there were mount­ings on the side and rear doors and at the front.

The armoured cars were delivered by Wolseleys between March and June 1915 but the supply of “pom poms” could not keep pace and the cars for only two batteries were equipped with guns by the end of April, when they were sent to France. The guns for a third battery were received during August and the Brigade was not fully equipped until September. Spares for the “pom poms” were in short supply and during the Summer of 1915 there was a shortage of ammunition for the guns. In spite of these difficulties, the R.M.A. A.A. Brigade did good work, the first aircraft claimed to be shot down was on 30 April, two days after the unit was first in action, and in all around twenty enemy machines were hit and probably destroyed up to the time that the unit was re-equipped with 3-inch A.A. guns (on different mountings) during the Summer of 1917 and the “pom pom” was withdrawn.
The “pom poms” had a rate of fire of four rounds per second and could put up a formidable barrage. Their range was short, originally under 3000 yards, but by improvements in fuses and ammunition this was progressively increased so that eventually enemy reconnaissance and bomber aircraft were forced to operate at over 10.000 feet, where they were far less effective. During their time in France, the guns were frequently operated from the same positions for extended periods, and the scale of spare armoured cars turned out to be far in excess of the requirements of the Brigade and so some of them were handed over to the Royal Naval Air Service Armoured Car Division during 1915 and one car, at least, fitted with a “pom pom” ended up in Russia with Locker-Lampson's force.
Sixteen other armoured cars, very similar in appearance to the Pierce-Arrows were built by Wolseley Motors on Peerless chain-drive chassis. These were built for Russia and delivered in 1916.