The gas mask is a mask used to protect the user from inhaling airborne pollutants and toxic gases ("Gas"). You would need gas masks in the trenches to survive inhaling those gases.
The Entrenching tool is a collapsible spade used by military forces for a variety of military purposes. Survivalists, campers, hikers and other outdoors groups have found it to be indispensable in field use. Modern entrenching tools are usually collapsible and made using steel, aluminum, or other light metal("Entrenching"). Soldiers in trenches found the entrenching tool useful to dig the trenches for safety during war.
In the protection of a trench, a soldier's most vulnerable area was his head. The steel helmet was invented for the protection of heavy objects falling from above. These helmets reduce head injuries by 75% (Brosnan).
First Field Dressing Pack
The First Field Dressing Pack was used as an soldier's kit. The intention was that men would have some means of dressing their wounds when medical personnel were not close at hand. The pack contains two dressings, along with safety pins for fastening them ("First").
In the trenches, rifles can help the soldiers defend them self while in war. Snipers and spotters who used the weapon praised its semi-automatic capabilities as an improvement. They didn't have to reload after every shot (Smith).
Brosnan, Matt. “10 Things That Could Have Saved Your Life in the Trenches.” Imperial War Museums, 2016, www.iwm.org.uk/history/10-things-that-could-have-saved-your-life-in-the-trenches.
“Entrenching Tool.” Wiki, Wikipedia, www.google.com/search?q=entrecnhing+tool+%5C&rlz=1CAACAJ_enUS683US689&oq=entrecnhing+tool+%5C&aqs=chrome..69i57.3678j0j7&sourceid=chrome&ie=UTF-8&safe=active&ssui=on. Accessed 25 Mar. 2017.
“First Field Dressing Pack.” Imperial War Museums, www.iwm.org.uk/collections/item/object/30025941.
First Field Dressing Pack. Imperial War Museums, 2016, www.iwm.org.uk/collections/item/object/30025570.
“Gas Mask.” Wiki, Wikipedia, en.wikipedia.org/wiki/Gas_mask. Accessed 25 Mar. 2017.
Rifles. Pinterest, www.pinterest.com/katelynj10/world-war-i-weapons/.
Smith, Stewert. “United States Military Weapons of War.” The Balance, copyright, 2017, www.thebalance.com/united-states-military-weapons-of-war-4058538. Accessed 15 Sept. 2016.
Steel Helmet. Varusteleka.com Military and Outdoors, Lillhonga.fi, www.varusteleka.com/en/product/spanish-m65-steel-helmet-surplus/34363. Accessed 24 Mar. 2017.