The train driver told me about driving freight trains
before the safety systems were controlled technologically. Certain
signal boxes had control of the line between their area and the next
designated control area but the signalman would telephone the central
control officer for advice before he set the signals for trains passing
through his area.
The old fashioned telephone was fixed high on the wall so the central control officer became known as the Man on the Wall because when he stood to speak, he seemed to talk to the wall.
So when a train was approaching the signal box, the signalman would contact the Man on the Wall and then he would set the signals for the train. Following the instructions he received, he could advise the driver to proceed immediately, or at caution, or to stop. Sometimes he would advise the driver to put the train into a siding, leaving his line clear until another train had passed and circumstances had changed.
The Man on the Wall was never off-duty, he could be contacted twenty-four hours, seven days a week and he knew the whereabouts of every train.
Where there was an unattended signal box, the driver would ask the foreman on his train to talk direct to the Man on the Wall for advice because no train could proceed safely without consulting him.
Every train crew understood the importance of the Man on the Wall and no other advice could over-ride his.
The train driver’s story is a picture by example that God is our "Man on the Wall". He is never off-duty and relying on His advice, we go, or stop, or proceed at caution. Sometimes He advises us to go into a siding until the road ahead is clear but His advice cannot be superseded without endangering ourselves and everybody around us. Our freight is safe, our crew is safe and everyone around us is safe while ever we take the His advice.
He sees the conditions ahead and says even "Before they call I will answer, while they are still speaking I will hear," (Isaiah 65:24). But He offers more than just travelling advice, He "richly blesses all who call on him," (Romans 10:12), so even as we make the call to ask His advice, the blessing is already ours. It is a present from the Man on the Wall to us twenty-four hours, seven days a week.