Soldiers in the army have usually something like a kit-bag, see sack, weekend bag or duffel bag. This not to use in the combat field but to take all their clothing and gear from army base to army base or from their barracks to home during weekends. These bags are usually very simple. In case of a duffel bag it is usually a one compartment bag with rings and a clip to close it instead of zippers. Most duffel bags have just one strap to throw over your shoulders. The US army duffel bag however is one of the few designs with two straps so that it can be worn as a (improvised) backpack. To improve the possibility of carrying the duffel bag as a backpack the bag has a rectangular shape instead of a cylindrical shape. A round shape will flip sidewards all the time when you have it on your back. A flat shape will be much more stable.
The Outdoor Gear Review made a very nice movie on YouTube about the US Army GI duffel bag. The movie below is from Coach Helder who actually used the bag while being in the US Army. He also wrote a blog about this duffle bag.
The US army duffle bag is widely copied by other armies (such as Thailand) and also by companies for the civilian market. Some models are more or less exact copies while others are just inspired or roughly based on the original US army duffel bag. Examples of exact copies are 5ive star gear, Rothco, Fox Outdoor, Mil-Tec and 101 inc. Besides the original olive green color these copies are often also available in other camouflage colors.
US Army inspired duffel bags / backpacks
Nowadays there are duffel bags for sale that are clearly inspired by the US army model. Where the US army models (the modern ones) are made of 1000 denier nylon the civilian ones are made of canvas. The padding on the shoulder straps of the original model are quite small; 5 cm * 35 cm. Luckily the padding on the civilian model is much wider and longer with 8 cm * 48 cm. This ensures that the weight in the pack is more evenly distributed over your shoulders making it much more comfortable to wear. The pressure per square cm of square inch is simply less. The US army model is quite big with 30 * 30 * 75 cm = 67,6 liters. And this is not the biggest one among army issued duffel bags. Many armies have much bigger duffel bags. The civilian ones are available in different sizes. The one we tried was available in two different sizes 23,4 liters (20*26*45 cm) and 33 liters (20*30*55 cm). The colors that you can choose from is black / gray, olive green and khaki.
The 33 liter size is perfect for usage as a carry on bag in a airplane. Because it is a soft shell bag you will always find a place to stow it away. The maximum amount of luggage that we were able to fit in it was 10 Kg. That also meets the requirements for hand carry on luggage from most airlines. The bag also has the perfect size to fit on a scooter bike like a Honda Scoopy. You don’t have to secure the bag with straps and your feet can still stand on the foot plateau. When you stop for a drink or a visit to waterfall or so it is easy to grab your bag and take it with you. The pictures below are taken on Bali, Indonesia.



An extra feature is that the top flap inside the bag has two pockets and a clip for your keys.

A nice feature that isn’t mentioned on any of the websites that is selling these bags is that the bottom is padded with soft and probably water repellent material. In this way your luggage is extra protected. It also prevents to much wear and tear on a single layer of fabric. Usually duffel bags from the army don’t come with a feature like this. However many backpacks issued by the armies around the world have a rubber protection at the bottom.


Both duffel bags have a small pocket next to the grip handle. Originally this was for storage of the marching orders of a soldier. Additionally it is also perfect to store a padlock in.


Both the original US army duffel bag and the civilian made duffel bag are super lightweight for what they carry. The US Army duffel bag weighs only 0,95 Kg and the civilian one (33L) weighs only 0,85 Kg. If you compare it to very sophisticated bags this is very low. For example the Thule Subterra 34L weights 1,2 Kg, the Aer Flight Pack (23,6L) weighs 1,3 Kg and the Tortuga Homebase Backpack 32L weight 1,0 Kg.

Two different versions
The dufflebag-backpack is on the market in two different versions: One with D rings on the shoulder straps and a new improved one with ladder buckles on the shoulder straps. The metal D rings are slippery so that the straps easily loosen and the bag sags down while caring it on your back. The ladder buckles have a tight grip at the straps so that the bag stays in place when you carry the dufflebag on your back.

Another small difference is that the dufflebag with the ladder buckles has loops at the base of the bottom. Perhaps only intended as extra reinforcement for the shoulder straps but it also gives yo the opting to slide a military belt through. By doing so it becomes a backpack with hip belt.
Other commercial duffel bags based on the US Army model
Some manufacturers make (US army style) duffel bags from a fashion perspective. Like the Nylon-top-load-duffle-bag on www.arket.com.
Another example is canvas duffel bag the from the Danish company Nordisk. It is shown in this Thai YouTube movie. This has the single shoulder sling that was used on the classic canvas version of the US Army duffle. But in the two shoulder straps that were used on the modern nylon version of the US Army duffel bag. www.nordisk.eu
Also Austrian rucksack manufacturer and Austrian Army supplier ESSL makes a duffel bag that is highly based on the US Army duffel. www.essl-rucksack.at
Even the WW2 version of the us army duffel bag is still reproduced. This one didn’t had shoulder straps but instead just one big carry strap for over your shoulder.
www.atthefront.com
Also inspired by other backpacks ?
This US army style duffel bag/backpack might be inspired by other bags as well. The small inner pocket with mesh, a zipper and a key clip is almost identical to the Exped Torrent 30 waterproof backpack. Also seen in this YouTube movie.
The thin but wide shoulder straps look a bit like the straps of another US army backpack: The MOLLE II 3 Day Assault Pack. Be aware that the original army issued version op this backpack has the same extra fabric stitched over the sides of the straps. Civilian made copies don’t always have this. The shoulder straps are clearly seen in this YouTube movie.

Summary of pros and cons:
Pro:
- Smooth design without all kinds of straps and pockets hanging outside the bag.
- Lightweight, although the weight could be lower when fabrics like ripstop nylon or CORDURA® fabric Nylon was used.
- Theft resistant; Can be locked with a padlock.
- Wide and long padded shoulder straps. Surprisingly comfortable to carry.
- Cheap
- Can endure some rough handling.
- Carry on size and weight.
- Grip handle on the side
- No zippers or buckles that can brake.
- Soft padding at the bottom.
Con:
- The version with the D-rings has the tendency to loose the shoulder strap adjustment because the straps slide easily through the D-ring construction when you use the bag. (The ladder buckle version doesn’t have this issue).
- No name tag
- Most likely not water proof.
Available at:
www.aliexpress.com
www.miltact.com
www.outdoorguerrilla.com
www.everjerrys.com
www.greengoblue.com