HMCS TORONTO tour: Auxiliary Machinery Tour

My previous post on touring HMCS TORONTO covered the propulsion machinery spaces in both the forward and aft engine rooms. Forward and aft of these spaces are the AMRs, or Auxiliary Machinery Rooms. The primary inhabitants of these two rooms are four 850 kW Deutz MWM diesel generators that provide electrical power to the ship. 

It was an interesting opportunity to be able to photograph these two spaces, as the aft AMR was largely intact, while the forward AMR was in the process of being torn apart in preparation for being handed over to the Halifax Shipyard for refit.

Diesel generators intact inside their enclosures in the aft AMR. The enclosure is covered in access ports that can be opened to allow maintenance access all around each generator. The enclosure contains much of the sound produced by the generators, and is also useful in the event of fire.

Looking along the catwalk between the two generators. 

A memorial in the aft AMR for former crewmember who has "crossed the bar".

While the aft AMR was mostly intact, the forward AMR was in the process of being dismantled prior to refit.

In the forward AMR, the diesel engine inside the enclosure is exposed. 

Warships interiors are cramped, with every available space taken up by some piece of equipment - even the spaces below the deck plates. The bilge in the ship is often a treasure trove of lost tools that are lost by the ship's company during routine maintenance tasks, and they can't be retrieved until the ship is next stripped down prior to refit. As I recall, one of my tour guides was looking forward to retrieving a flashlight lost just weeks earlier.

The power generated in the two AMRs is routed to the rest of the ship to power everything from weapons systems, combat and navigation sensors, and the ship's hotel load (lights, etc) via two main electrical switchgear sets. 

Aft main switchgear.

The two AMRs don't just contain power generation equipment, but also have an assortment of other equipment as well. 

The AMRs also contain other equipment, such as R2D2 here (otherwise known as a fuel centrifuge for removing water and contaminants from the ship's fuel supply).

Another auxiliary machinery space, one deck below the weather deck and to the aft of the ship, is the "tiller flat" where the steering motors are found.

The steering gear is mounted on the rudder post. It is powered by two hydraulic motors, with the starboard steering motor seen to the left through the door.

The port hydraulic steering motor.

HMCS TORONTO tour - Propulsion Machinery

HMCS TORONTO in January 2015, returning from her last deployment prior to her mid-life refit.

As the last HALIFAX class frigate to enter the midlife FELEX refit program on the East Coast, TORONTO was the last ship of the class here in Halifax remaining more or less in her original configuration. She was therefore my last opportunity to photograph the interior of this class of ship for posterity prior to some fairly major changes.

The propulsion plant of the HALIFAX class represents somewhat of a departure from earlier RCN surface warships. The three earlier classes (Tribal, St. Laurent family, & IROQUOIS) were fitted with two pairs of steam or gas turbines, for cruise and boost power (though in the case of the ST. LAURENT class, they were designed with cruise turbines that were either later removed or not fitted at all to later ships of the class). The HALIFAX class, while retaining two gas turbines for high speed, uses a single diesel engine for fuel efficient operation at cruising speeds. They also have a unique gearbox arrangement to allow a CODOG (Combined Diesel or Gas) arrangement. I believe these ships were the first RCN warships to use diesel propulsion since a batch of BANGOR class minesweepers commissioned during the Second World War.

Also unlike previous ships, the cruise and boost powerplants are installed in separate compartments. The propulsion diesel is situated in the aft engine room, and the gas turbines are fitted in the forward (and larger) engine room along with three gearboxes. 

While I was doing my tour, the diesel propulsion engine was actually being dismantled piece by piece and removed through a hole in the deck. 

Looking down into the aft engine room.

Looking down into the aft engine room, but from one deck lower.

A series of "soft patches" in the various decks above the engine room can be removed to allow the removal of engine components. We were there just in time to see one of the turbo-chargers being lifted out. In contrast, I believe the gas turbines can actually be removed more or less in one piece, up through the funnel - thought it requires disassembly of the enclosures and trunking. This has allowed gas turbines to be replaced in foreign ports during the extended deployment of some ships.

Turbo-charger being removed by FMF Cape Scott personnel. A turbine on the exhaust stream powers a compressor that increases the amount of combustion air in the diesel's 20 cylinders, allowing the engine to produce more power.

As I recall, SEMT-Pielstick (recently rebranded as MAN Diesel) designed the 20-cylinder, 8,800 shp, propulsion diesel specifically for this class of ship - I don't know if it has been used anywhere else. This led to some teething issues early in the life of the class. The engine is normally hidden inside an enclosure, but during my visit the enclosure was opened up and the engine partly torn down. (Clarification: the engine block itself was not removed, but the engine was stripped down prior to the refit.)

Partly torn down Pielstick diesel inside its enclosure. To the left of the photo is the forward bulkhead.

The yellow-and-black port propeller shaft runs aft in the aft engine room. I had wanted a good picture of the "El Diablo" artwork seen here in the background, but unfortunately the enclosure panel it was on was the one removed to access the diesel, and was partly obscured. It appears in a Combat Camera video taken during one of TORONTO's extended deployments just prior to her refit.

The diesel's drive shaft leaves the engine and heads to the forward engine room, where it intersects with the centreline of the ship's Royal Schelde cross connect gearbox. The cross connect gearbox allows the single diesel to drive both propellers.

Sketch showing my understanding of the ship's propulsion layout. (P) = Port, (S) = Starboard, PD = Propulsion Diesel, PGT = Propulsion Gas Turbine, Prop = Propeller, GB = Gearbox, CCGB = Cross Connect Gearbox, ER = Engine Room. The dashed line represents a bulkhead.

Looking forward in the forward engine room. The Royal Schelde cross-connect gearbox is in the immediate foreground, while the port and starboard gearboxes and gas turbines are partly hidden behind piping.

In the forward engine room, there are two General Electric LM2500 gas turbines that provide 47,500 shp to take the ship up to 30+ knots. They are installed side by side immediately forward of their port and starboard gearboxes. Aft of the port and starboard gearboxes is the Royal Schelde cross-connect gearbox, from which the propeller shafts exit. The gearbox setup is intended to allow the following configurations:

• diesel engine driving either or both shafts
• port gas turbine driving either or both shafts
• starboard gas turbine driving either or both shafts
• both gas turbines driving both shafts simultaneously.

In a CODOG powerplant, propulsion diesel and gas turbines can not power the propellers at the same time.

Port gearbox looking forward.

Starboard gearbox looking forward, with the back end of the gas turbine enclosure visible.

In the event of engine or gearbox failure, considerable redundancy is provided. Some examples:

• If the diesel engine fails, either or both gas turbines can be used for propulsion. 
• If either gas turbine fails, either the diesel or the remaining gas turbine can provide propulsion.
• If the cross connect gearbox fails, the gas turbines can be used through the port and starboard gearboxes (although they are dedicated to a single propeller shaft). 
• If either or both port and starboard gearboxes fail, the diesel engine can still work through the cross-connect gearbox, or a remaining gas turbine can work through its gearbox.
• If either propeller or shaft experiences problems, power can be routed to the remaining shaft.

I'm sure there are additional failure modes here that I have not considered. Machinery in previous classes of warships were designed to operate with partial submersion of the engine room, so these ships may also be so designed (although the diesel and gas turbines of modern warships may or may not be more susceptible to submersion than the steam turbines of previous warships). The engines are all shock mounted which also reduces sound transmission.

Looking forward, the starboard propeller shaft leaving the cross-connect gearbox.

Port propeller shaft leaving the cross-connect gearbox. When the ship pulls into port, and stops her engines, the ship's company holds a 50/50 lottery on which number each shaft will stop on, with part of the proceeds going to charity.

Port propeller shaft looking aft.

The GE LM2500 gas turbines belong to one of the most widely-used families of marine gas turbines. I once heard an RCN commander comment in the mid-2000s that he was surprised that GE got the contract, where such things normally go to the lowest bidder, and the LM2500's had been so reliable to that time. They are installed inside enclosures that provide sound and fire isolation, to prevent detection by sonar and provide a measure of containment in the event of fire. There are fire suppression systems inside each enclosure.

Looking aft between the two gas turbine enclosures. The two doors visible access the interior of the enclosures.

Looking through a window in the enclosure at the compressor stages of the starboard LM2500 gas turbine.

As with the IROQUOIS class that I have written about earlier, the cruise and main engines can be controlled locally (via the local control panel in the aft end of the forward engine room), from the machinery control room (MCR), or from the bridge. 

Looking to starboard along the catwalk at the aft end of the forward engine room, with the local control panel to the right.

Head-on photo of the local control panel.

The local control panel in the forward engine room is part of the Integrated Machinery Control System (IMCS). This panel can control and monitor many pieces of equipment, from the three engines and three gearboxes, as well as the hydraulics for the controllable pitch propellers. If you look at the top of the panel, you can see the schematic outlines of the two gas turbines, with the various gearboxes outlines below.

As with the previous IROQUOIS class, the HALIFAX class has two controllable pitch (CP) propellers. The propeller blades can be controlled to provide different degrees of forward or reverse thrust. The engines, and in particular the gas turbines, generally have speeds at which they are more efficient than others. The propellers allow the engines to be kept within their most efficient operating parameters, by controlling the propeller pitch rather than the engine speed. The CP props are also useful in transitioning to reverse thrust - gas turbines only spin in one direction.

Although many systems are being replaced as part of the mid-life FELEX refit, the engines and gearboxes shown here will continue to propel these ships into the third decade of this century.

HMCS PRESERVER: Tour of electical power generation and the bow thruster

Where the power generating equipment is located across multiple spaces, some of which I have already covered, I decided to break out my summary of power generation onboard PRESERVER into a separate blog posting. As a result, a few photos and descriptions from previous postings may get repeated here. This should be read in coordination with those earlier postings covering the engine room, boiler room, and machinery control room. 

I will also cover the bow thruster, as it is powered by a rather large diesel engine that isn't in the engine room. As always, I will note that I am by no means an expert on these systems, and am relying on information gleaned from my guides during my tour as well as my own assumptions. Mistakes are my own!

Electrical power generation onboard a warship is a particularly critical capability, required to start propulsions engines, run hotel loads and combat systems, and is therefore designed for redundancy. In PRESERVER, this means that three types of generators (2 steam turbines, 2 diesels, and 1 gas turbine) are distributed across three different spaces (engine room, boiler room, and forward of the bridge respectively).  

Port turbo-alternator (steam turbine generator).

While at sea, the two 1000 kW turbo-alternators (installed port and starboard in the engine room) would normally provide the majority, if not all, of the ship's power requirements. Being steam driven, these generators require steam from the boilers, so these generators would not be used while the ship is alongside with cold boilers. Therefore, in order to provide power to start up the boilers, power is required from other sources.

Poor quality video capture of the two diesel generators, looking forward and to starboard.

The two 500 kW diesel generators are located port and starboard in the boiler room, between the two boilers - this should put them on the ship's centreline. The diesel generators are more or less self contained, and can begin generating power fairly soon after a cold start. The diesels would provide power to the boilers to get steam up, after which power generation would be transferred to the turbo-alternators, and the diesels would be shut down to save fuel. Not only are the diesel generators separated from the turbo-alternators by being located in separate spaces within the ship, they also rely on a separate fuel source, providing additional redundancy. 

Gas turbine generator.

Located forward on No.1 deck on the starboard side of the deckhouse forward of the bridge is the emergency generator compartment, home to a single gas turbine generator. I believe this is the same model as used in the IROQUOIS class destroyers, albeit in a different type of enclosure. If so, this is a Solar Saturn unit rated for 750 kW. Gas turbine generators have the advantage of being able to run up to full power from a cold start almost instantaneously, and therefore they have great value as emergency generators that can come online very quickly when other sources of electricity unexpectedly fail. In addition to being able to be started using local controls, this generator could be fired up remotely from the Machinery Control Room (MCR).

In the photo above, we are looking at the generator enclosure, with the generator itself being installed inside. As I recall, the exhaust pipe for this generator exits the ship not quite six feet above deck level on the starboard side, and is therefore a bit of a head knocker for those not paying attention.

Another angle on the Solar Saturn gas turbine generator.

It is my assumption that the gas turbine generator would not typically be used either alongside or at sea, apart from occasionally being exercised, and that it would be reserved for emergency use. I could be wrong.

Gas turbine local switchboard.

There is a local switchboard installed in the same compartment as the gas turbine generator.

For lack of a better spot, I will also cover the bow thruster here. 

Bow thruster diesel engine.

Being rather large, and driven by a single shaft, these ships are not the most maneuverable. During a refit at some point, during the 1990s I believe, both PRESERVER and PROTECTEUR received bow thrusters to reduce their reliance on tugboat assistance when leaving port or coming back alongside. The bow thruster is effective at speeds of up to 5 knots, and is driven by its own direct drive diesel engine. This diesel does not generate electrical power, but rather is connected mechanically to the bow thruster by a vertical shaft.

Bow thruster diesel engine

I  believe the vertical cylinder on the end of the diesel engine in the photo above is the top of the direct drive shaft leading down to the bow thruster. I am assuming that either the diesel would have to reverse direction in order to allow the bow thruster to direct thrust from port to starboard, or the impeller would need to have adjustable pitch blades. I didn't think to ask at the time, so I don't know how this is done. 

Bow thruster impeller tunnel.

The bow thruster impeller itself is necessarily installed very low in the ship's hull, and we descended several ladders to reach this compartment. I believe this photo is taken looking to port. The impeller for the bow thruster is installed in a water-tight tunnel, as seen here, which allows it to throw water out either side of the ship. The tunnel is roughly as tall as a man, and the direct drive shaft enters the tunnel at top-centre in this photo.

In the compartment above the bow thruster are the guts of the blackwater (sewage) treatment system onboard PRESERVER. The blackwater tanks are in close proximity, and no space on a warship goes unused.

HMCS IROQUOIS: Electrical Power Generation (Corrected)

Warships have large electrical power requirements, in order to run everything from heating and the lights, to galley equipment, electric fire pumps, sensors, and weapons systems. On IROQUOIS class destroyers, the Auxiliary Machinery Room (AMR) houses two 750 kW Solar Saturn gas turbine generators and one 1000 kW diesel generator to provide this power. A third 750 kW Solar Saturn is located forward of the bridge at deck level, in the port side of the deckhouse that formerly housed the Sea Sparrow launcher pre-TRUMP. If truth be told, I managed to get myself completely turned around in the AMR, and didn't take enough video and wide shots to help properly orient myself in the photos that follow, so some of my typical directional commentary will be lacking in this post. I didn't get a clear picture in my head of where each piece of machinery is located.

Looking down into the lower level of the AMR. Port propeller shaft at left of ladder. The AMR is a very crowded space that houses a variety of equipment, not just the generators.

In the 1960s when the IROQUOIS class was designed, gas turbines provided the best "bang for the buck" in terms of high power from a compact package, so the Solar Saturns are the primary power source. As with the propulsion engines, all the generators are housed within skin-tight enclosures that serve to insulate the surrounding space from noise and, in extreme events, fire. They are also generally shock mounted, but I have no specific details regarding this.

The Solar Saturn gas turbine generator in the main engine room with the cover rolled back.

The two Solars in the AMR are located port and starboard on the upper level of this space. During the time of my tour, two of the three Solar Saturns onboard had been dismantled and transferred from IROQUOIS to ATHABASKAN for spare parts on the latter ship. ATHABASKAN is the last remaining IROQUOIS class destroyer remaining in active service, and was on deployment at the time of this tour.

No.2 Solar Saturn gas turbine generator, looking forward in the AMR.

Possibly to hedge their bets, a diesel generator was also included (originally a 500 kW Fairbanks Morse opposed piston engine, replaced during TRUMP by a 1000 kW Detroit Diesel). It is installed at the forward end of the AMR's lower level, between the two propeller shafts. The local control switchboard for this generator was retrofitted during the TRUMP refit, to accommodate the larger 1000 kW generator.

The diesel generator sits inside this enclosure, the interior of which doesn't appear quite as easy to access as the rolling enclosures for the Solars.

1000 kW diesel generator inside its enclosure through an open port.

Local control switchboard for the diesel generator. Built in 1987, this would have been a retrofit during the TRUMP refit.

All the electrical power on the ship is routed through the main switchgear, which is located elsewhere in the ship.

Main switchgear compartment.

As with the propulsion gas turbines, all the generating equipment is controlled remotely in the Machinery Control Room (MCR) which I will cover in a subsequent post on this blog.

Correction: Previous versions of this post were mistaken in the location of all three Solar Saturn generators. In fact, only two are located in the AMR (upper level), and the third is located at deck level in the deckhouse forward of the bridge. Many thanks to members of various Facebook groups for setting me straight.

HMCS IROQUOIS: propeller shaft & running gear

Following on from my earlier post with a tour of IROQUOIS' engine room, this post will trace the path of the propeller shaft after it leaves the gearbox. After departing the gearboxes, each propeller shaft passes through a thrust block (which transfers the thrust of the propeller to the hull) and several plummer blocks (which support the shaft along its length).

Looking down into the AMR. A yellow and black propeller shaft runs down the left side of the photo.

  Immediately aft of the main engine room, where the propulsion machinery is located, is the Auxiliary Machinery Room (AMR). The AMR houses three Solar Saturn 750 kW gas turbine generators plus one 1000 kW diesel generator, as well as numerous other pieces of smaller equipment. The port and starboard propeller shafts also pass through the AMR.

A propeller shaft (painted yellow & black) runs through the AMR heading aft (e.g. to the right).

Plummer blocks support the propeller shaft at the aft end of the AMR.

Due to the shape of the hull and there being two of them, the shafts must pass through not only the AMR, but also a DFO service tank, and finally the Gland Compartment before passing through the hull.

Starboard propeller shaft running through the Gland Compartment. I believe the blue hose is a hydraulic hose from the hydraulic pump for the CP props.

CP prop hydraulic pump unit.

Modern warships, including the IROQUOIS and HALIFAX classes, often use variable-pitch or controllable-pitch (CP) propellers, where the blades of the propeller can be rotated to different pitches. This is necessary because gas turbines can not be run backwards, and otherwise it might be necessary to include an extra "reverse" turbine on each shaft as was done with steam powerplants in the previous generation of warships. The CP prop allows the gas turbines to run in the same direction at all times, and the transition between forward and astern power is handled by the pitch of the propeller blades. The hydraulic pump that controls the pitch of the propeller blades is located in the Gland Compartment, two compartments aft of the AMR.

The starboard shaft passes through seals and exits the hull in the Gland Compartment.

The other side - the port shaft exits the hull.

Port propeller shaft intermediate support strut.

Port variable (or controllable) pitch propeller. A V-shaped strut supports the shaft just ahead of the propeller.

Starboard "running gear": the propeller shaft showing both intermediate and V-shaped support struts.

The original variable pitch propellers fitted to IROQUOIS and her sisters were only four bladed and were shaped differently (as I recall), and new propellers (presumably quieter and more efficient) were retrofitted at some point, possibly during her TRUMP refit in the early 1990s.

Update: The port variable pitch propeller, removed from HURON before she was sunk, is on display at the Naval Museum of Alberta in Calgary.