So you think you know about Trains? - Pt 2

[Saturnr]

Answer to the August 23rd question

Smoke deflectors are used to prevent drifting, to get the smoke up, instead of letting it drift and obscure the engineer's view. They help with draft. The smaller kind are called Elephant Ears, like on UP 4-6-6-4 #3977. Most engines which had the smoke deflectors were built or rebuilt/modernized during or after WWII (1940s).

 

[wkwood]

The deflectors helped to channel air along the sides of the boiler. This channel of air naturally prohibited smoke and other particles of combustion from flowing down the sides of the locomotive. This especially helped visibility especially in tunnels where the escaping steam and smoke from the boiler didn't have much room to escape and would funnel around the sides of the train naturally.

 

[ZecMurphy]

What is the purpose of ‘smoke deflectors’ when fitted to a steam locomotive?

The purpose of smoke deflectors, when fitted to a steam locomotive, is to ‘lift’ or ‘push’ the smoke and steam from the chimney up higher so as to not obscure the crew’s view out of the cab.











This weeks question:
What is the purpose of ‘interlocking’ on a signal lever frame?

 

[nicky9499]

Interlocking prevents conflicting movements of a set of switches for safety reasons. For example, a crossover on double-track may be interlocked so that the switches can only be aligned to diverge together.

 

[SBLimey]

What is the purpose of ‘interlocking’ on a signal lever frame?​

The interlocking is to prevent the setting of conflicting signals on a single track.

 

[ZecMurphy]

What is the purpose of ‘interlocking’ on a signal lever frame?

The purpose of interlocking, on a signal lever frame, is to prevent conflicting train movements from being permitted on signals and turnouts. For example, if you have two lines merging to one line, the signals and turnouts will be interlocked so that the signals can only be changed when the turnouts are set correctly, and so that the turnouts can only be changed when all applicable signals are set to stop.
















This weeks question:
On a steam locomotive, what is the purpose of the expansion link?

 

[rweber95]

Interlocking also provides other safety functions, at least on the systems that I've worked.
1. The levers in the frame are sequentially numbered. To set a path you must pull a series of numbered levers and you must pull them in a specified order. The interlocking mechanism will prevent you from deviating from that sequence.
2. Once a sequence has been complete, pulling the last lever in the sequence locks that path and you can't undo it until the time lock is set and timed out. This feature prevents the tower operator from making changes in the face of an oncoming train.

Bob Weber

 

[jjanmarine3]

IfI remember correctly from 40 years ago... ...the expansion link moves up or down positioning the valves correctly allowing steam to be admitted to the pistons for forward or reverse movement.

 

[ZecMurphy]

On a steam locomotive, what is the purpose of the expansion link

The purpose of the expansion link on a steam locomotive is to both allow the locomotive’s direction to be reversed, and adjust the cut-off of the valves to improve performance at higher speeds. Both of these functions are achieved by moving either the expansion link or the radius rod up and down, which in turn changes the timing of the valves that admin steam into the cylinders.














This weeks question:
On a steam boiler, what is an economizer?

 

[Bill69]

An economiser is used to increase the efficiency of a boiler to raise steam. Economisers come in various different forms, they can be as simple as a steam heated cylinder used to heat the water from the tender before it goes into the boiler.

Cheers,
Bill69

 

[ZecMurphy]

On a steam boiler, what is an economizer?

The economizer, sometimes known as a ‘feedwater heater’ (particularly on steam locomotives), uses the exhaust gasses after they have left the boiler tubes to pre-heat the water so as to improve the fuel efficiency of the boiler, since less fuel will be required to heat the water. On steam locomotives, these use steam (either live steam or exhaust steam) to pre-heat the water.














This weeks question:
What were the names of the four streamlined steam locomotives that hauled the Spirit of Progress in Victoria??

 

[NSWGR_46Class]

S 300 Matthew Flinders
S 301 Sir Thomas Mitchell
S 302 Edward Henty
S 303 C J La Trobe

 

[ZecMurphy]

What were the names of the four streamlined steam locomotives that hauled the Spirit of Progress in Victoria?

The names of the four streamlined steam locomotives that hauled the Spirit of Progress were Matthew Flinders (S300), Sir Thomas Mitcheel (S301), Edward Henty (S302), and C.J.Latrobe (S303).































This weeks question:
What is the purpose of the blowdown on a steam locomotive??

 

[JIb228]

This weeks question:
What is the purpose of the blowdown on a steam locomotive??

To allow the crew to "blowdown" the boiler, or let off all the steam in a safe manner prior to shutting down the locomotive.

 

[MrRail]

It allows out steam and water when shutting down a boiler, but can also remove, and help prevent build ups of boiler scale.

 

[ZecMurphy]

What is the purpose of the blowdown on a steam locomotive?

The purpose of the blowdown on a steam locomotive is to rapidly release water/steam from the lowest part of the boiler so as to ‘blow out’ sediment, and unwanted minerals.










This weeks question:
On a steam locomotive, what is the purpose of a superheater??

 

[transitguard]

This weeks question:
On a steam locomotive, what is the purpose of a superheater??

From a thermodynamics standpoint, a superheater heats the steam out of the saturated steam region and into the superheated region of the phase diagram. When the steam is superheated, it is less likely to condense when energy is harvested from it such as when it goes through a turbine or reciprocating engine.

In practice a superheater also causes higher efficiency in most cases because it is increasing the heat transfer area between the hot combustion gases and the steam. This allows more energy to be absorbed from the burning fuel.

 

[ZecMurphy]

On a steam locomotive, what is the purpose of a superheater?

The purpose of a superheater is to further heat the steam, using the otherwise unused heat from the exhaust gasses in the boiler. This superheated steam, being at a temperature above it’s ‘vaporisation’ point (the point it changes from water to steam - this temperature changes depending on boiler pressure), does not carry any water with it and is at a high enough temperature to not condense within the cylinders whilst the locomotive is in operation. Superheated steam also provides greater expansive energy, which will either improve the performance of the locomotive or increase it’s fuel efficiency (or both).

















This weeks question:
What is the purpose of a ‘Shelf’ coupler??

 

[4449tj]

it is a coupler that cannot be uncoupled from another coupler from vertical motion. it has catches on the bottom and top to keep this from happening. Shelf couplers are used on ALL tank cars and also on any hazmat cars. this is so that the coupler can't puncture the tank in a derailment.
TJ

 

[DaveL]

Yup, what he said.....except I would not use the word "cannot" or the word "can't". Having seen a wreck or two, anything is possible....."cannot & can't" are too narrow.

DaveL