We kregen dit boek voor onze bibliotheek uit de nalatenschap van Henk Schreurs, via Aat Hoogervorst.
Het is een uitgave van GRS bij hun 75 jarig bestaan in 1979.
ABOUT THIS BOOK-GRS has been supplying signal systems and equipment to railroads and to rail transit since 1904. This book is our way of celebrating our 75th anniversary, of saying, "Thank you”, to our many friends.We offer it as a means to help those who are entering the signaling field. It is not a complete course in railway signaling but an introduction to this fascinating and complex subject. We think it will be useful as an over-all view of signaling systems, their principles of operation, and how these principles are applied.