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ahead of the battleship. The conventional diesel -powered submarines

couldn't meet this speed requirement.

So in 1913, the Sexborough steam -powered submarine, designed by the

Director of Naval Construction, was passed to Vickers Shipbuilding for a

detailed design.

K -13 was one of 12 K -class submarines ordered in August 1915.

Construction began at Fairfield's Govan shipyard in October 1915 and launched on

the 11th of November 1916.

K -13 was notable for its size, 103 meters in length with a beam of 8 meters

a draft of 6 meters.

For propulsion on the surface it had two water tube boilers, each powering a

geared steam turbine which ran twin three -blade propellers capable of

reaching 24 knots.

When submerged, the screws were operated by four electric motors with speeds up

to 8 knots.

It had a diesel generator for charging batteries on the surface.

The K -13 had an operating range of 12 ,500 nautical miles on the surface and

nautical miles underwater.

On the starboard side of the boiler room was a watertight passage connecting the

turbine room and the torpedo compartment.

Each end of this passage was watertight and midway a bullseye looked into the

boiler room.

There were a total of nine watertight doors and four 94cm boiler room air

having mushroom cupboards.

The K13 is operated by a crew of 52 personnel, including officers.

On Monday the 29th of January 1917, the K13 is at Gairlock, an open sea lock at

Argyll and Bute, Scotland, carrying out its acceptance trials, which is the last

step before Fairfield officially turns over the submarine to the Admiralty. The

K -13 achieved a record speed of 23 knots, earning the honor as the world's

fastest submarine.

It completes a successful dive to 25 .3 meters for around two hours, leaving the

crew and contractors and evaluators overjoyed. The ship's test is almost

complete. The last item on the checklist is to confirm the funnel covers and the

boiler room air inlet are in fact watertight.

The evaluators haven't been able to check the funnel covers during the dive

because the boiler room has been too hot. So they schedule a short 15 -minute

dive after lunch.

After they ascend, the crew opens the boiler room air inlet to allow the room

cool down for the next dive.

As the K -13 prepares for the second dive, the regular crew of 53 officers

crew are accompanied by 11 Admiralty and subcontractors, 11 directors and

employees of Fairfield, and two Royal Navy officers of the K -14, acting as

observers to gain experience.

The submarine's location is a short distance from Shandon Hydropathic, a

retreat in Helensburgh, Scotland.

The water is calm and the tide is high as the crew prepares to dive.

The command is given to close all hatches. Lieutenant Commander Godfrey

captain of the K -13, makes the last look around before closing down the

tower hatch.

He orders half speed ahead on both motors.

When they reach a position opposite the Shandon Hydro, he gives the order to

dive. Setting the hydroplanes to diving angle, the submarine smoothly slides

below the surface.

Lieutenant Commander Herbert orders trim level at 6 meters, but the submarine

continues to dive.

An engine room crew member reports that the boiler room is flooding.

The watertight door to the stern section is quickly closed and locked, even

though it means certain death for the men trapped in the compartments aft of

engine room bulkhead.

In the control room, the civilian guests realize something's wrong. The death

gauge is showing the submarine is sinking.

far more quickly than intended.

Their ears hurt as the air pressure changes rapidly, compressing the air

them. Even though the watertight bulkhead door is shut, K13 has voice

run between compartments. These voice pipes have their own shuttle valves.

As water floods the stern, the influx of water compresses the air into the other

compartments through the voice pipes.

Lieutenant Commander Herbert orders an emergency surfacing maneuver.

The hydroplanes are moved to hard rise and the ballast tanks are blown clear of

water. But the K -13 continues to descend rapidly.

Buoyancy in a submarine is controlled with water in ballast tanks.

More water makes the submarine negatively buoyant and sink.

To create positive buoyancy underwater, the submarine pumps air into the ballast

tanks to push the water out.

Essentially, the size of the air bubble in the tank offsets the weight of the

submarine.

With the boiler room flooding, the weight of the submarine steadily

and the ballast tanks can't compensate for the extra weight.

A jet of water comes through one of the voice pipes and soaks the switchboard,

causing a short circuit which blows the fuses and ignites the cables.

The control room fills with a white, choking smoke.

The crew quickly put out the fire with their bare hands and closed the valves

the three voice pipes leading from the control room to the aft of the

In quick succession, orders are given to close all watertight doors and to drop

the forward 10 -sun keel which serves as a weight.

But that doesn't stop the submarine's uncontrollable descent.

Moments later, its stern settles on the muddy bottom of the lock at 15 meters of

water. The K -13 rests on the bottom with a slight lift to port and an

inclination of 4 degrees up at the bow.

Lieutenant Commander Herbert makes a crew count and assesses the damage of

submarine. 31 of the men aboard the submarine are unaccounted for,

drowned in the flooded stern section.

Only one watertight door separates the remaining survivors from the flooded

compartment.

Located in the stern section is the engine room with various controls.

Without access to those controls, K13 is unable to blow any water or oil out of

the aft tank, nor can it release the other 10 -ton aft drop keel. And the air

supply is low. A considerable amount has been used up trying to blow water from

the ballast tank.

And a large quantity of air spent in the previous dive hasn't been replaced.

On the bright side, the batteries are fully charged so they have light and

can pump water or compress air.

The crew turn on the compressor for a short period to equalize the pressure

inside the submarine with the water pressure on the hull. After discussing

chances for rescue, the crew realize that they have to wait for around 18

before they can expect a response from the surface.

They are not expected to surface until 1530 and it will be dark by 1600 which

will likely delay any rescue until the next day.

On the surface, the captain of the E -50, another submarine on diving trials,

watching the K -13 dive.

The captain notices something's wrong.

He drops a buoy to mark the spot then reports the incident.

The alarm is raised and a call is made to Fairfield where a rescue and salvage

team is immediately organized.

Six hours later, a gunboat and two salvage tugs leave for Gerlach.

The gunboat Gossamer arrives on scene at midnight.

It has a diving suit but no diver, so the team has to wait a few hours for a

rescue diver.

When he arrives, he quickly dons the suit and goes into the water.

But the suit is old and it hasn't been maintained.

It leaks and the diver almost drowns. The tugboat Thrush also arrives on scene

but it has neither suit nor diver. So the rescue team has to wait for a dive

suit to be brought to the site.

Inside the K13, Professor Percy Hillhouse, the naval architect from

calculates the remaining air and how long it lasts.

He believes the 48 survivors only have eight hours at most.

To extend their air, they make use of the submarine's compressed air supply.

With the use of the air compressor the crew allows a small quantity of used air

to escape into the torpedo room and forces the used air back into the air

cylinders. What I think they're trying to do is keep the pressure at a constant

level and cycle the air. This provides new air but with increasing levels of

carbon dioxide.

Since the air is foul breathing gets harder and more laborious. They keep

movement to a minimum so they use less oxygen in the air.

Some try to sleep to conserve air.

The following day at 0800, the crew of the K -13C streaks of light through the

periscope. Looking through the port window on the side of the conning tower,

they make out the wire guard rail of the submarine's top side.

They decide to raise the mast of the K -13, hoping it'll indicate their

when it breaks the surface.

But as they raise the mast, the top hits one of the salvage vessels and is bent.

and the rescuers don't see the signal. A short while later the crew hear heavy

footsteps and tapping outside the hull. They respond to the tapping sound to

establish communication by means of Morse code.

They don't hear a reply and so they dismiss the tapping sound as a possible

hallucination because of the bad air they've been breathing.

The crew go back to waiting and hoping someone will come to rescue them. But

diver hears the tapping from inside the submarine and heads to the surface to

report his findings.

As the crew waits, they start the pump to clear water from the midship torpedo

room to reduce the weight in the submarine and prevent water from

batteries under the control room.

Lieutenant Commander Herbert and Commander Francis Goodhart, captain of

sister vessel K -14, who's there as an observer, discuss a plan for one of them

to reach the surface.

Lieutenant Commander Herbert, who's captain of the K -13, has to be the last

on board to make sure everyone gets out before him. So Commander Goodhart will

attempt to reach the surface.

The men prepare the conning tower for Commander Goodhart to escape.

The conning tower is a heavy brass casting above the control room.

It measures 1 .6 meters long, 1 meter wide and 1 .2 meters high.

To climb into the conning tower, Commander Herbert climbs up through a

the control room with a watertight hinge cover opening upwards into the tower.

Inside the conning tower, the aft portion of the roof has an exit hatch

balanced watertight cover opening upward into the wheelhouse.

The forward portion of the conning tower's roof has a dome with a height of

meter. The dome has a projector compass which projects the compass bearings onto

the glass, allowing the helmsman to see the compass bearing when he's looking

out to sea.

To prepare for the escape, the projector compass is removed to create more space

in the conning tower and dome.

As the commanders prepare the escape plan, Professor Hillhouse takes a tin

cylinder casting and puts a note in it. The note lists the names of the

survivors, the description of their condition and their needs.

The tin cylinder is covered with red bunting to make it visible at the

waterline. He instructs Commander Goodheart to bring this with him and

it as soon as he clears the wheelhouse.

This is their backup plan in case Commander Goodheart doesn't make it.

After finishing their escape plan preparations, both commanders removed

their clothes, entered the conning tower and closed the lower hatch below them.

The men inside the control room lock the lower hatch and open a high -pressure

air valve to pressurize the conning tower.

Without this pressure, the water pressure would keep the outer hatch

The crew hear a rumbling and gurgling sound inside the conning tower which

signals that the outer hatch has been opened and water flows in.

Inside the conning tower, the two commanders open the upper hatch and

the dome as the conning tower fills with ice -cold seawater.

The sound of the high pressure air deafens their ears and a thick fog fills

upper space.

The dome creates an air pocket where both men wait until the conning tower

the wheelhouse are flooded with sea water.

As the water reaches waist level, Commander Goodheart signals to

Commander Herbert and plunges into the cold water making his way to the upper

hatch. This leads to the wheelhouse where he plans to swim towards the aft

where the exit door is located.

Lieutenant Commander Herbert follows to close the upper hatch behind him. As he

steps past the upper hatch, the compressed air pushes him upwards into

wheelhouse. By pure luck, he's carried by the escaping air aft and up through

the hatch in the aft end of the wheelhouse roof.

As he struggles to swim, he's carried by the ascending air to the surface.

He surfaces close to the salvaged ship Thrush, and strong hands grab him and

pull him on board.

Lieutenant Commander Herbert's first words are, Where's Goodheart?

The rescuers didn't see Commander Goodheart, nor the tin cylinder.

As Commander Goodheart steps out of the conning tower's upper hatch, he's shot

violently upwards by the rushing air, hitting his head on the roof.

of the wheelhouse which knocks him out. His body is stuck in the forward part of

the wheelhouse and he drowns.

At the control room the men are waiting for Lieutenant Commander Herbert's

tapping signal so they can drain the water inside the conning tower.

Once the water in the conning tower has been drained they can unlock the lower

hatch so he can rejoin them. But the men don't hear Lieutenant Commander

Herbert's signal.

After a period of waiting they assume that both commanders have escaped to the

surface.

At the surface, Lieutenant Commander Herbert loses no time briefing the

about the details of the submarine and the survivors.

The first -hand report of conditions inside K -13 informs the rescuers how to

proceed. The priority is to supply air to the sunken submarine to keep the men

alive. With additional air, pressure can be built up to support the leaking

engine room bulkhead. If the bulkhead gives way, water will flood through the

forward compartments and drown the survivors.

Experts from Fairfield are consulted and plans are drawn up.

Armoured hoses are prepared that will fit into the existing forward high

pressure air connection.

These openings have valves or watertight covers that are accessible from the

inside and outside the submarine.

Hose fittings and adapters are made by the engine department at Fairfield and

the high pressure air hose is supplied by the submarine E50.

At 1800 on Tuesday, the crew hear Morse code tapped on the hull to let them know

that a high -pressure hose is connected to K -13's air system.

The crew slowly opens the inboard valve connected to the high -pressure hose,

but seawater pours into the submarine instead of air. They tap out a message

inform the divers what's happening. The crew waits again while the diver

disconnects and overhauls the air pipe.

The problem is traced to ice blocking the line.

At 0400 on Wednesday, 37 hours after the accident, the air hose is connected

again and clean, dry air flows into the submarine.

The crew allows a little air to circulate into the hull and then they

their exhausted air cylinders.

At 0500, once the crew finish filling several banks of cylinders, they start

blow out the forward ballast tanks. These are the seven foremost external

and the internal tanks forward of the boiler room.

As they blow out each tank, they watch the bubble on the fore and aft spirit

level to see if the bow is lifting.

As tank after tank fills with air, they watch as nothing happens.

When they pump air into the last tank, the bubble finally moves.

The bow slowly ascends and breaks the surface of the water.

The stern of K -13 is stuck in almost 4 meters of mud, so the submarine balances

at a steep angle.

The crew can't move around inside the submarine.

They lose their footing and slide to the bottom of the compartment.

The rescuers latch a steel wire underneath the hull of K -13 and lift

until it's standing clear above the surface.

Left -handed Commander Herbert sees an opportunity to bring the survivors out

through the torpedo tubes, but K -13 slips back slightly, leaving the bottom

the tubes just below the waterline.

At 0630, another wire is attached to the hull and a flexible 10cm protective

hose is attached to the submarine.

A suction hose is passed through to draw out the stale air which is black and

foul. The crew can finally breathe in fresh air. But as they draw out the air,

there's a reduction in pressure and the boiler room bulkhead begins to leak

rapidly. The 10cm protective hose is large enough for the crew in the

and the topside rescuers to shout messages back and forth.

It's also big enough to pass small pieces of food.

The rescuers send a bottle of brandy to warm the spirits of the crew. And they

send milk and chocolate.

Lastly, they send a high -pressure air hose to add to the existing air supply.

This fills the cabin with more fresh air.

The crew learn that Lieutenant Commander Herbert is safe, but Commander

Goodheart didn't make it.

Inside the submarine, a connection on the compressor comes loose.

While reconnecting it, one of the men accidentally makes a short circuit which

blows the main fuse and everything goes pitch black.

The crew have to use hand torches to see what they're doing.

At the surface, the rescuers are trying to make a plan to rescue the crew. The

torpedo tubes can't be used because they're partially submerged below the

waterline. The rescuers decide to cut a hole in the foxhole or raised deck at

the bow of the submarine, pump out any water between the foxhole and the main

hull and cut another hole directly below it in the main hull.

The water can be removed in about 20 minutes and the holes can be cut by the

oxyacetylene torch in a few minutes more.

The crew are told to move forward and prepare to exit at the bow. The crew in

the submarine tear open a wood lining and climb up on top of the torpedo

then wait for the hole to be cut.

But 20 minutes turns into an hour and the cutting doesn't start.

At the top side, the rescuers are busy pumping out the water. As they pump

out, more water fills the compartment.

The crew wait restlessly in the dark and then they hear a rescuer shout, have

you closed the flap valve?

The submarine's superstructure has four square openings just above its

attachment to the main hull so that it will easily flood and drain when the

vessel submerges and emerges.

To prevent these holes from letting in water while sailing at the surface, flap

valves are fitted and controlled by hand wheels inside the vessel.

These were open for the diving trials.

The crew tighten the valves and the water level starts to drop quickly.

In a few minutes the inner hull is pumped dry.

Rescuers used the oxyacetylene torch to cut a 45cm square hole.

At 1500, 57 hours after K -13's trial dive, 46 survivors emerged

through the escape hole.

Of the total 80 crew members, officials and civilian visitors, 31 were trapped

and drowned in the stern section.

One died during the escape attempt and two were reported missing.

John Steele, Fairfield's foreman engineer, and Lieutenant Lane, an

-13, managed to open the engine hatch and swim for the surface.

Lane's body was found about two months later.

Steele's body was never recovered.

The diver discovered that the four air inlets to the boiler room were fully

open. These should have been closed before the signal engine room closed was

in the control room.

The accident wasn't a defect in the design or construction, it was operator

error. When the vessel was examined, the lever controlling the air inlet covers

was open.

The K -13 was salvaged on March the 15th, six weeks after the accident.

It was overhauled and recommissioned as K -22.

K -22 was eventually sold for scrap metal in December 1926.