Specifics of the development of emergency situations at the pipeline transportation facilities with accidental damage of the elements are considered. It is shown that the ability of the system to withstand process development of the progressive blocking of hubs should be estimated using the resistance index, which represents the average proportion of the damaged hubs, blocking which in a random order leads to breaking the connection with the source of all the disconnected consumers of the end product.

It is possible to increase resistance of the systems to the development of the process of progressive blocking using measures for protection of transport hubs. In this case, the efficiency of protection depends on the composition, structure of the system, as well as on the adopted protection scheme. Difficulties that occur in assessing efficiency of the adopted protection scheme are conditioned by the fact that the comparison of the systems resistance indicators with alternative options of protection is possible only at comparability of their network structures.

It is proved that comparable systems are comparable if they have the same number: consumer nodes, which can be disconnected from the source as a result of the development of the blocking process; damaged nodes able to transfer to a state of inoperability due to lack of appropriate protection; peripheral clusters with two or more consumer hubs and the same number of such hubs in each of them. In addition, the sequence of disconnecting from the source, both individual consumers and peripheral clusters with different numbers of product consumers, should be the same.
For comparable systems, the comparison of the values of indicators of resistance, performed by the method of simulation modeling, is the correct one and allows you to substantiate and make reasonable design solutions.