The Signalman’s fate is foreshadowed when the narrator remarks:
He had made his bed, and he lay upon it.
This initial mention of the "bed" is an observation of the signalman's passive helplessness in response to his bleak life circumstances. However, the signalman does not apply this same passivity to his duty as a signalman, as he feels responsible for any loss of life on the train tracks. He seemingly believes that although his fate is determined, deaths, as foretold by the ghosts, are not fated and he must therefore stop them. However, the narrator later uses the imagery of the bed when he sees a group of men huddled near the danger light to look at the dead body of the signalman:
Against its shaft, a little low hut, entirely new to me, had been made of some wooden supports and tarpaulin. It looked no bigger than a bed.
The signalman's initial belief of fate being sealed is proven right, as he was never able to make use of the hauntings to avoid his death. Whether he was actively trying to change fate or accept it, life and death came for the signalman anyway. While subtle, the foreshadowing of the signalman's set fate and the ghost's foreshadowing of a tragic event builds suspense by hinting that the signalman or someone around him will die, but the reader has to wait for the when and how.
Dickens uses the three ghost appearances to foreshadow death. However, the way the ghosts present to the signalman and the resulting tragedy differ each time. The only consistency between the three encounters is that the signalman is unable to prevent the fated tragedies.
The first ghost appeared only six hours before a train accident, waving and shouting in a way that seems to have foretold the narrator's first encounter with the signalman. The ghost's sudden harried appearance mirrors the swift tragedy of the accident and the attempts of the signalman to prevent the accident by following his duty. All the signalman could do was use his flags or lamp and shout, just as all the ghost could do was wave and shout, yet neither could prevent the crash. The train was too powerful for even the best signalman in England to stop. In the second encounter, the ghost appeared on the morning of the tragic death of a young lady on one of the trains with only a silent gesture of mourning. Similarly, there was nothing the signalman could've done to prevent the young woman's death, as it happened in the train car, so he could only mourn. However, the signalman explains that the third ghost is different from the other ghosts:
"The spectre came back a week ago. Ever since, it has been there, now and again, by fits and starts."
This repetitive haunting, marked by shouts, waves, and the ringing of the signalman's bell, is the most disruptive of the three and happens significantly before the actual tragedy takes place. The third ghost is reflective of the signalman's thoughts of his mortality. Everybody is aware they will die at some point and are reminded of this from time to time. The signalman's dismal line of work likely does not discourage these thoughts. However, even if he knows that one day he might die, that does not mean he knows when or how to prevent it. The failure of the ghosts' foreshadowing hauntings to prevent the tragedies emphasizes the signalman's helplessness in the face of death and industry. No matter how early or in what manner he is forewarned about the deaths, he can't prevent them.