Survival goes hand in hand with being able to find multiple uses for items to which you have access. Being able to adapt through ingenuity will help you through TEOTWAWKI. One such item that can serve several purposes is a 55 gallon drum. These come in both metal and plastic, and each variety will have slightly different capabilities. Plastic seems more versatile overall, but metal has advantages as well.
Probably the number one use for a metal drum is as a burn barrel or location for a heat source or cooking fire. Throw kindling and/or logs inside and ignite. The barrel will contain the fire and not allow it to spread, which is important in a dry forest area. Do keep in mind that the barrel will get extremely hot and refrain from touching it until long after your fire is put out. If you have access to metal grating that can work as a rack, turning your metal drum into a grill is also an option that will give you a nice, warm meal.
Another good use for a metal barrel is in the creation of thermal mass, which works by absorbing heat and releasing it gradually. If you were to fill a metal barrel with water and let sunlight hit it directly, you could stay close to that barrel throughout a cold night and experience warmth radiated from it. When the sun rises again, the process repeats as the barrel again absorbs heat during the day to give you access to slow seeping heat overnight.
Other possible uses for metal drums are as a storage location for grains, fertilizers, and compost. They can even be used as deer feeders if you have the means to position them properly.
Plastic drums cannot serve as a heat source due to the effect of fire on plastic, but they have plenty more to offer. Cut them in half length-wise and use them as planters for growing vegetables or keep the drum intact and cut holes in the sides out of which your vegetables can grow. This will give you the ability to house and nurture a fairly large garden all in one convenient location.
If you need a makeshift boat, look no further than plastic drums. Being airtight enables them to float, and they can support the weight of people and other raw materials necessary to create a floating platform. This makes them great for both a moveable boat that can be paddled to and fro or as a pier extending into the water for fishing. Just keep in mind that being round means that these barrels will roll in the water so they will need to be stabilized and fastened securely to the other components of your boat or pier.
When it gets cold, your animals will need shelter, too. Just because the SHTF does not mean you can ignore the needs of your animals. House both dogs and chickens in plastic drums to keep them warm and out of the elements. Animals also need feeders, and a plastic drum cut in half length-wise makes for a nice animal feeder.
Something else you and your animals both need is a drinking source, so set yourself up water collection barrels. The ability of each drum to hold such large amounts of water will help with your accumulation of rainwater and store it for you as well. This also correlates with the thermal mass strategy mentioned earlier as plastic barrels can act as sources of thermal mass as well.
Having 55 gallon drums on hand could prove to be a wise move due to their multiple uses and versatility. Just be sure to find food grade drums rather than those used to house chemicals to avoid making yourself, your family, and your animals ill. When you have completed all of your 55 gallon drum projects, you will have earned some relaxation, so take a seat and have a rest.