Origin of haversack
In historic Germany the word ‘hafersack’, meant oat sack. This was a small sack to carry horse fodder. It was a long, narrow bag that had a strap at the top and bottom, which was worn across the body from shoulder to hip. When it was adopted in England the f was changed to a v because of language usage.
haversack
http://www.yourdictionary.com/haversack
hav·er·sack
A canvas bag for carrying rations, etc., generally worn over one shoulder, as by soldiers or hikers.
It was generally square, measuring 12 inches per side with a button down flap. When empty it could be folded in three with an extra button on the back that allowed it to be fastened in this position. This was the original usage of the haversac in the British Army. Eventually, other armies adopted the haversack, but the need for more carrying capacity created a niche for an enlarged version. Thus, the rucksack was born.
http://www.militaryheritage.com/haversack.htm
In some countries the words are synonymous with each other, but the differences are clear. Haversacks are small with one strap, sometimes with one pocket but often with more. A rucksack has two shoulder straps, one large pocket and often many smaller ones. There are varying designs for these bags, some have a single pocket, others many. Commonly straps are added to allow other items to be attached to the outside.
http://www.vemra.org/blog/2016/8/6/haversack-how-to
What is now commonly known as a Haversack, in the British Army, was referred to as a bread bag. It is generally defined as a small bag with a single shoulder strap. In military use, it was usually made of undyed canvas or black canvas if you were in a British or Commonwealth rifle regiment, and was used to hold a soldiers food rations. (There will be a lot more about the haversack and its history, plus all about what was actually carried inside in a future blog post…)
The pattern for this haversack came from, “Soldiers’ Accoutrements of the British Army 1750 – 1900” by Pierre Turner. It is the 1880 General Service model. I’m using a 1oo% cotton canvas in black this time.
https://history.army.mil/html/museums/messkits/Field_Mess_Gear.pdf
Many people that don’t know the origins of a haversack often confuse it with a rucksack. For this reason a new name is often given to the sack: satchel. One such example is the Dungeons and Dragons magic item “Heward’s Handy Haversack”; from the definition this is a “rucksack” not a haversack.
D&D 5th Edition Compendium
This Backpack has a central pouch and two side pouches, each of which is an extra-dimensional space. Each side pouch can hold up to 20 pounds of material, not exceeding a volume of 2 cubic feet. The large central pouch can hold up to 8 cubic feet or 80 pounds of material. The Backpack always weighs 5 pounds regardless of its contents.
Placing an object in the haversack follows the normal rules for Interacting with Objects. Retrieving an item from the haversack requires you to use an action. When you reach into the haversack for a specific item, the item is always magically on top.
The haversack has a few limitations. If it is overloaded, or if a sharp object pierces it or tears it, the haversack ruptures and is destroyed. If the haversack is destroyed, its contents are lost forever, although an artifact always turn up again somewhere. If the haversack is turned inside out, its contents spill forth, unharmed, and the haversack must be put right before it can be used again. If a breathing creature is placed within the haversack, the creature can survive for up to 10 minutes, after which time it begins to suffocate.
Placing the haversack inside an extra-dimensional space created by a Bag of Holding, Portable Hole, or similar item instantly destroys both item and opens a gate to the Astral Place. The gate originates where the one item was placed inside the other. Any creature within 10 feet of the gate is sucked through it and deposited in a random location on the Astral Plane. The gate then closes. The gate is one-way only and can’t be reopened.
Below are different versions of haversacks and rucksack through time.
Runkle Plays Games 