Friday, July 30, 1915

Trenches – Ploegsteert

The Battalion War Diarist wrote for this day: “Patrol sent out under Capt. W.D. Adams, particulars of which appear in the Intelligence Summary, 1st Canadian Division, #13, August 1, 1915.” [1]

THIS DAY IN RMR HISTORY: “July 30th was a quiet day on the front, though some trouble was caused by enemy trench mortars.  At night a patrol, under Capt. W. D. Adams, moved into No Man’s Land and returned with valuable information.  Later the enemy opened rapid fire, as if fearing an attack, or planned to launch one.  Nos. 1, 3 and 4 Companies of the 14th “stood to” during this demonstration, which died down shortly before dawn.” [2]

30 July 15_A

Gas alarm rattle

“British Empire troops used a variety of devices as anti-gas alarms throughout the war. Low-maintenance alarms could be improvised by converting empty large-calibre brass cartridge cases into bells or gongs, like dinner bells. These alarms were installed at regular intervals in the front trenches and sounded if a gas attack was suspected.

Installing bells, gongs, or air horns in the trenches was a relatively simple matter, but a way to spread the alarm was also required on roadways and temporary positions further to the rear. Air horns and bells were less practical in such instances, because they were not easily portable, and could not readily be sounded by troops on the march. As a temporary measure, soldiers might bang their bayonets on their helmets, but this was not ideal, as it involved removing the helmet and leaving the head exposed.

The gas alarm rattle offered a better solution, because it was lightweight, portable and had a simple, inexpensive design. There was some fear that sound of the gas alarm rattle might be mistaken for machine-gun fire and ignored. However, this was not the case, and the gas alarm rattle was a reasonably effective local alarm.

Soldiers were also trained to spread the word of a gas alarm verbally, tapping on the shoulder of the next soldier, and passing the news down the line. As the gas alarm rattle became more common, some, upon suspecting the presence of gas, would shout ‘rattles’ as they donned their respirators.”

GAS ALARM RATTLE: “This rattle produced a loud, distinctive noise to warn of a gas attack. Troops had to don respirators quickly in order to avoid death or chemical burns.” By holding the device by the long dowel handle on the left of the picture and swinging the weighted arm on the right in a circular motion, the thin flexible wood strip through the centre moved over the cogged gear like wheel on the centre shaft. This created a loud “rattling” or “clacking” noise which served to warn those nearby of the approach of gas.

Gas alarm


GAS ALARM HORNS (Strombos Horns): The Strombos Horn was a First World War period British gas alarm horn. “By May 1916, Strombos horns were positioned every quarter of a mile along the front line. The compressed air cylinder allowed the horn to be sounded for over a minute in the event of a gas attack.

The original IWM caption (circa 1920) reads as follows: ‘British Strombos Horn Set. In box,with one compressed air cylinder. Devised by the British as an alarm signal of cloud gas attacks soon after the first cloud gas, April 1915. It is a sort of trumpet operated by compressed air contained in cylinders carried for that purpose. Its note is penetrating and can be heard, under good conditions, for three or four miles. With the advent of shell gas, and particularly mustard gas (July, 1917), the number of gas attacks, which previously occurred only at intervals of two to four months, increased considerably. This made it not only impossible, but also inadvisable, to furnish sufficient Strombos horns, a cumbersome and technically delicate instrument, for all gas alarms, as gas shell attacks are comparatively local. The use of the Strombos horn in such cases caused troops who were long distances from the area attacked to take precautions against gas, with consequent interference with their work or fighting. To meet these local conditions metal shell cases, steel triangles, watchmen’s rattles, klaxon horns and similar methods of giving the alarm were adopted.’” [7]

[1]   War Diary, 14th Canadian Battalion, The Royal Montreal Regiment, July 30, 1915.  Library and Archives Canada, Ottawa
[2]   R.C. Featherstonhaugh, The Royal Montreal Regiment 14th Battalion C.E.F. 1914-1925, Montreal, The Gazette Printing Co., Ltd., 1927, pg. 65.
[3]   Gas Rattle, Canadian War Museum, Cat No. CWM 19880212-107
[4]   “Gas Alarm Rattle,” Artifact Backgrounder, Canadian War Museum, Ottawa,
[5]   Gas Rattle, Canadian War Museum, Cat No. CWM 19880212-107
[6]   “Strombos Horn, Mark II,” Imperial War Museum; IWM (FEQ 847);
[7]  Ibid