The Portable Self-Contained Ballast Vibration Tamping Machine model VPS is designed to perform occasional ballast tamping under all type of railway sleepers (wooden, concrete or steel). By its design the machine provides exceptional lightness (the lightest available on the market), autonomy and ergonomics. It is a railway dedicated machine. By its unique design, the Portable Self-Contained Ballast Vibration Tamping Machine model VPS is a portable and self-contained machine to ensure occasional tamping operations. Its integrated petrol engine makes it a compact machine and avoids the use of generating sets and feed cables. In-depth research has been carried out with regards to the weight, ergonomics and vibrational features, in order to: Considerably reduce the weight of the machine; Considerably improve the ergonomics (handles positions, masses balances, optimum height, etc.); Considerably reduce the level of vibrations felt by the operator and to the petrol engine; At the same time gain excellent tamping quality.