Blog 145 - TITANIC - PART V - ENGINES AND ENGINEERS

TITANIC - PART V - THE ENGINES

MORE ABOUT THE THE TITANIC’S ENGINES, ENGINEERS AND MACHINERY

Triple Expansion Engine - Lower Side

Triple Expansion Engine - Upper Portion showing the LP Unit

The X head and thrust shoes of the TE Engine

In Red - Boiler Rooms

15 ft diameter, 20 ft long boilers - 29 of them

A cut out section of the Scotch Boiler - More than a 100 years later, the basic design has not changed

Top : Boilers in the shop

Below ; Boiler spaces in the Boiler Room

Evaporators

Evaporator circuit

Evaporator capacity 60 tons / day

Forced Draft Air for Boilers 

The Double Bottom included 4 tanks for Fresh water, Feed Water, Salt Water. There was space for 5700 tons of Ballast Water. 1000 tons of Fresh Drinking Water

The ‘Black Gang’ were about 160 in number and were the ones who did all the stages of work in keeping the boilers fired and producing steam. Being always dirty, black with coal, they were kept out of the passenger’s eyes and had separate quarters far away from the path of passengers. Maybe the Third Class passengers saw them. Their quarters were right up in the  foc’sle. They hardly saw the light of day, as their quarters were directly connected to the Boiler Spaces. (In today’s world, those spaces are part of the Forepeak Store, with the Bulbous Bow right forward.

The Firemen worked on a 4 on ~ 8 off work day. This was an age old tradition, followed to this day, if the Engine Room was manned. (These days, there are Unmanned Machinery Spaces Engine Rooms that are not manned in the night hours). 

The amount of coal consumed by the boilers was around 600 tons per day. Which means that much of coal had to be manually transported from the coal bunkers to to the boiler spaces, after which they had to be shovelled into the furnaces. Back breaking work.

There were ‘trimmers’ working the coal bunkers, who not only had to shovel coal but also do it in such a way that the vessel does not list.

Boiler Rooms and Engine Room Spaces

The Parsons Turbine

The concept of the steam powered turbine was still in its infancy, with most ship owners preferring the Triple Expansion Steam Engine to the Turbine Engine. I keep referring to steam turbines, as its invention brought about an effect which reverberates even today as Jet Propulsion, Gas Turbines, Hydro Power Units, all depend on turbines.

(I think the first steam turbine powered vessel was the ‘Tubinia’, built in 1894).

The Cunard Lines were well ahead of the White Star Line. Their 1906 ships the Mauretania and Lusitania were both powered by two HP Turbines and two LP Turbines for ahead thrust and two LP Turbines for astern thrust. All were direct drive, no reduction gearing. Because of this, the vibrations were high. Coal consumption for the Boilers was also high, more than a 1000 tons a day. But speeds were high.

But the disadvantage that the Triple Expansion Engine of those days was that, being a reciprocating engine, it could not run beyond a certain rpm (in those days), limiting the speed of the ship. There were technical considerations which limited the size of the TE Engines.

But it was not, then, realised that the Parsons Turbine had no such limitations. Though the efficiency was low, compared to the TE Engines, it could give more power to propel the ship at awesome speeds.

Cunard Lines’ Lusitania and Mauretania were the first ships to use direct-drive steam turbines to win the Blue Riband. The Lusitania had four turbines, two high-pressure and two low-pressure, that drove four propellers. The Mauretania had two extra stages of turbine blades in its forward turbines, making it slightly faster than the Lusitania.

In a way, the ‘Titanic’ was a ‘hybrid’. It used the exhaust steam of the 4 Low Pressure Cylinders to run a Turbine that was connected to a centre shaft and propeller, increasing the overall plant efficiency, at a time when hardly anyone bothered about thermal efficiency.

To a modern Marine Engineer, the Triple Expansion Steam Engine will seem formidable and dangerous as most parts - except for the pistons inside the cylinders - are in the open. But you can actually touch and feel the bearings and moving parts without the use of laser thermometers. Maintenance is easy, as long as you know what to do. You can fine tune the performance of each cylinder, on the (reduced speed) run, by adjusting the slide valve or shuttle valve. For me, it used to be a wondrous occasion when the Triple Expansion Engine driven dredgers used to go out on trial runs, during my apprenticeship days.

So the Titanic had 3 propellers, 2 outer 3 bladed propellers - each connected to a Triple Expansion Engine - and a centre 4 bladed propeller connected to a Parsons Turbine. There are conflicting reports and analyses about the 3 bladed and 4 bladed propellers. See photograph, purportedly of the Titanic below. But the rudder looks to be a hollow rudder, not the single plated rudder that the Titanic had.

One of the conundrums as far as propellers’ configuration was concerned, was the fact that the two outer propellers were right handed, whereas the centre propeller was left handed.

The Triple Expansion Engine’s Heavy Bed Plates

5 iron castings bolted together, each almost 200 tons in weight

The four cylinder support columns, closely resembling the A - Frames of today’s Marine Diesel Engines

4 Cylinders - HP, IP, and 2 x LP Cylinders

Slide valves for the Double Acting Pistons

The Cross Head and Shoes to take the side thrust of the engine

Boiler Steam pressure 215 psi (lbs / sq inch)

Reaches the engine at 210 psi

Enters HP Cylinder at 210 psi

Exhausts into Medium Pressure Cylinder (or Intermediate Pressure Cylinder)

Enters into Medium Pressure Cylinder at 78 psi

Exhausts into both Low Pressure (LP) Cylinders

Enters into LP Cylinders at 24 psi

Exhausts at 9 psi

Enters the Turbine at 7 psi

Exhausts at 1 psi (much below atmospheric pressure, at near 100% vacuum state)

Nearly 250 ft long shafts

The Shaft Tunnels ( 3 of them) - Greaser Lubricating the bearing(s). (I have worked on ships with long shaft tunnels - it is a different experience)

Thrust Blocks to take up the thrust of the Propellers

Thrust Block’s Thrust shaft and Collars which transmit the thrust to the ship’s hull

Shows the Midships Turbine Room

Shows the hundreds of Turbine Blades being installed

A close up view of the Turbine Blades

The 410 ton Low Pressure Turbine - although built for Hull 433, it was the same as the Titanic (Hull 401), developing 16000 shaft horse power

25 Engineers to operate the three Engines.

Consumed at least 40% less coal than Cunard Lines’ Lusitania.

With the Boilers roaring red hot flames, the reciprocating engines thundering, the turbine whining, the propellers churning the ocean, the Titanic would have been forging ahead, the machinery working like a harmonic mechanical system.

Hundreds of pieces of auxiliary machinery 

Pumps, water filters, electric motors, evaporators, boilers, heaters, coolers, condensers, hydraulic machines, valves.

Some of the Engineers - All of whom gave up their lives - My Humble Salutations

The Engineers were manning the pumps to pump out the water from all the breached areas, even though the ingress of water was more than the capacity of the pumps.

The Firemen kept maintaining steam in the Boiler Rooms where the flooding was less, shovelling coal standing in a foot of icy cold water.

The steam was needed to keep the steam turbines of the generators running, for electricity for running the pumps and for general lighting on the ship. The lighting was most important for the passengers who, otherwise, would have needed to contend with itch dark corridors and decks.

The Electricians kept working, switching from one circuit breaker to the other, in order to maintain supply.

They kept to their posts till it was no longer possible. The water in the aft boiler spaces had risen to the furnace level.

Their act of gallantry and sacrifice gave the ship at least another hour of life.

Because of that extra hour, all lifeboats ad collapsible rafts could be launched.

The Chief Engineer was Joseph Bell, who kept motivating one and all.

All were given a choice to leave and escape, none did. All stayed.

There were 25 Engineers and 10 Electricians - none survived.

Of the ‘Black Gang’, there were a total of 163 Greasers and Firemen - 4 survived the sinking. Practically all of them were from Southampton.

Memorial to the Engineers who gave up their lives on the Titanic

At South Shields, Southampton, UK

This section is mostly sourced from ‘Oceanliner Designs’ You-Tube presentation titled ‘A Complete Guide to Titanic’s Engines’.

AR