  Hardy Cross originally proposed a method for analysis of flow in networks of
conduits or conductors in 1936. His method was the first really useful
engineering method in the field of pipe network calculation. Only electrical
analogs of hydraulic networks were used before the Hardy Cross method. A
problem with flow resistance versus electrical resistance makes these
electrical analog methods obsolete. The method by Hardy Cross is taught
extensively at faculties, and it remains an important tool for the analysis of
looped pipe systems. Engineers today mostly use a modified Hardy Cross method
which considers the whole looped network of pipes simultaneously (use of these
methods without computers is practically impossible). A method from a Russian
practice published during the 1930s, which is similar to the Hardy Cross
method, is described, too. Some notes from the work of Hardy Cross are also
presented. Finally, an improved version of the Hardy Cross method, which
significantly reduces the number of iterations, is presented and discussed. We
also tested multi-point iterative methods, which can be used as a substitution
for the Newton-Raphson approach used by Hardy Cross, but in this case this
approach did not reduce the number of iterations. Although many new models have
been developed since the time of Hardy Cross, the main purpose of this paper is
to illustrate the very beginning of modelling of gas and water pipe networks
and ventilation systems. As a novelty, a new multi-point iterative solver is
introduced and compared with the standard Newton-Raphson iterative method.
