YOU'RE NOT AS STRONG AND YOUNG AS YOU THINK YOU ARE!
Do not underestimate the task of moving a dozen railway sleepers. The muscles between your wrist and elbow are seriously put to the test! Most railway sleepers are pretty heavy, so it makes sense to lift within your capability and remember to bend your knees and not your back. Spending a week or two in bed with a strained back is agony and such a waste of life. Avoid your macho tendencies and attempts to beat the 'Carry the railway sleeper' record by the world's strongest man or the 'toss the railway sleeper competition'! It is unwise to mix railway sleepers and alcohol. By all means bribe people to help you, but it is recommended to serve the drinks and vol au vents afterwards. Carrying the end of a heavy railway sleeper with someone who's been drinking is a recipe for disaster. They'll either drop it on you, or cause you to fall ceremoniously backwards into the herbacious border.
Consider creatively using straps, trolleys and wheelbarrows. Some railway sleepers are simply TOO HEAVY to be safely carried down the garden. For example the 2.6m x 300mm x 175mm size of tropical hardwood railway sleepers CANNOT be lifted by mere mortals. They are too heavy. (120kg - 140kg each). You'll need a forklift machine or an extensive search in your local parish magazine for recently furloughed Olympic weightlifters.
TAKE CARE WHEN LIFTING RAILWAY SLEEPERS!
Wear sensible boots (not sandals, flip flops or crocks) and strong gloves. Beware of trapped fingers when one person lifts a sleeper while the other is still trying to get their hands underneath. It makes sense if one authorative looking person is 'in charge' of the lifting, i.e. "I'll lift my end of the railway sleeper first, and then you do yours". Look after your back, fingers and toes and take your time. Lifting a railway sleeper on your own to prove your Herculean strength is a sad inadvisable pastime. A back injury will often last a lifetime! End of sermon!