How would you write out, in words (or letters, anyway) the sound of a passing train?

GrungedlGrungedlGrungedlGrungedlGrungedlGrungedlGrungedlGrungedlGrungedl

HRRNNnnnnnnnnnnnn

GrungedlGrungedlGrungedlGrungedlGrungedlGrungedlGrungedlGrungedlGrungedl

Either that, or "I think I can, I think I can, I think I can, ..." :)

Clickerty clack, clickerty clack

My wheels are singing over the track.

To let you know I'm on my way

Aaaar aaaar my whistle will say.

But as I pass I make a different tone

Aaaar oooo, aaar oooooo I moan.

Click clack, click clack as I slow down

Shhhhhhhh, my steam is heard all over town.

Klink, klink my couplings come together

As each carriage they serve to tether.

One answer is avant-garde such as : Artichoke

Another answer is by a reference to other moving objects: a tin-whistle, pots-and-pans

Another reference is by onomatopoeia [I checked, I spelled this properly] such as: "Curchuffle", "Poot-Moot", or "Braze-Darling" or otherwise metallic

Ding-ding-ding-ding is typical of the feeling, in conventional language [the New Yorker magazine would inevitably use this, nothing else could be chosen except perhaps "tin whistle" or "brassy din" or something vague like "steam noise"]

Bro-ma seltzer, Bro-ma seltzer, Bro-ma seltzer. ( speeding up.

or just chugging along.)

( Approaching a crossing ) Wooooooo, woo, woo, woooo...

( Approaching the stayion ) Woo, woooo, woo woo.

Ding-dang, Ding-dang, Ding-dang. ( Bell )

( Then for a dead stop, they let off the steam ) Pshyiiiii i i i

I would use - "Click-a-de clack, Click-a-de clack.

Use all, part, or none.

Good luck.

Called "onomatopoeia," a train's noise would be like a clatter chink clank, intervals of ta-dunk (pause) ta-dunk, a bell's ting-ting, ting-ting, the horn's baleful waa waa, honk, whine.

Choo-choo, choo-choo, ch'boogie, woo-woo

Woo-woo, ch'boogie, choo-choo, choo-choo, ch'boogie

Take me right back to the track, jack

I think you got the classic onomatopoeia down.

I'd probably write it, "CH sh sh sh CH sh sh sh CH sh sh sh CH sh sh sh."