In short – not always. When considering alignment of a complete shaftline, the weight of the shaft, loads upon it, the components mounted on it and the movement of the hull or other structure supporting it under load need to be considered. In most cases a computer model of the complete system is used to predict the movement of the system under various load conditions. The outputs from this simulation include any slope or offset required within the bearings in order to ensure optimum support of the shaft in operation. It will also give expected bearing loads at various points along the shaft which can be used to check operation by raising the shaft and measuring the force required (jack up method).