Vimy Flight

The four replica Nieport XI biplanes of the Vimy Flight visited Halifax over the weekend. Originally due to arrive on Friday, weather kept them at Greenwood until Saturday, arriving in time for a flypast over Citadel Hill around 11:30 am. 

When we first spotted them, the middle two were popping some smoke.

After their flypast, all four headed over to CFB Shearwater to land, and two of the aircraft were walked backwards down the hill to the Shearwater Aviation Museum (they apparently weigh in the range of 550 lbs each). To move the aircraft, one pilot lifts the tail while another pushes from the front.

The pilot of this plane is Allan Snowie, author of "The Bonnie - HMCS BONAVENTURE". 

Here is one of the aircraft with two re-enactors from the Citadel in period uniform.

The aircraft are apparently built at 7/8 scale as compared to the original planes. I don't know the reason behind the size discrepancy, although it may have something to do with the requirement to fit four of these into a CC-177 Globemaster III for the trip to France and back so that they could fly over the memorial at Vimy for the centennial.

Lots of bright colours!

The engines were originally rotary engines, apparently - I'm not sure what they are using here. I suspect the red battery inside isn't accurate either.

The arrow actually serves a purpose, though you don't have to use an arrow. The original aircraft were fitted with splitters to prevent the cables from rubbing together, and someone started using an arrow for this purpose and it caught on.I'm guessing the plastic wire ties holding them on are not historically accurate.

The planes are all built of wood, reinforced with wire cable, and are covered with fabric, as were the originals. There are a few modern touches, however, especially when on looks into the cockpit.

I generally don't take selfies, but apparently I did here - can you spot me?

There are a few modern touches in the cockpit, including radios and instrumentation that would not have been available during the First World War. I'm assuming they also carry GPS.

One of the two aircraft is fitted with a Lewis gun mounted on the top wing, just over the cockpit.

The Lewis gun was an automatic machine gun perfected during the First World War. On aircraft, it was fitted without the cooling shroud seen on land-based weapons, presumably to save weight.

I strongly suspect the original aircraft didn't have an iPhone charging cable.

A close-up of the Lewis gun mounted on the upper wing.

This aircraft carries multiple dedications.

All four aircraft took off again on Saturday afternoon, and headed north to a small airfield outside Windsor, NS. They have a schedule on their website, which they do not seem to be following all that closely.

The cross-Canada tour began in Nova Scotia around May 6, and will continue west from here, apparently skipping Newfoundland & Labrador.

For lack of anywhere else to mention them, and also aircraft related, I will also show an interesting sight that flew overhead while I was cutting some wood outside just before sunset last night.

A flight of what I assume are three airliners headed from New York to London, all flying in a line. I had to choose between having trees or power lines in my shot. I chose the trees.

I liked how the contrail was petering out behind the last aircraft.

I'm assuming the third and final aircraft was a Boeing 747, but I am only going by the four engines and rough shape of the fuselage.

Vickers 3"/70 Twin A.A. Mark 6 mounting

Earlier today I saw a discussion around the guns used on the ST. LAURENT, RESTIGOUCHE, MACKENZIE, and ANNAPOLIS classes of destroyer escorts that served in the RCN starting in the 1950s, in particular the Vickers 3"/70 and the FMC 3"/50.

The latter was used on all four classes (originally both fore and aft on the ST. LAURENT class, forward on the ANNAPOLIS class, and aft on the RESTIGOUCHE and MACKENZIE classes), while the former was used only as the forward mounting on the RESTIGOUCHE and MACKENZIE classes. 

I have previously written a bit about both mountings on the Hazegray and Underway website, where I variously wrote:

About the 3"/50:

"Mountings started out open to the weather, and fibreglass and aluminum gun shields were added later. The shields were relatively fragile, and photos often show the forward mounting facing aft to protect it from storm damage.

Mounted on the foc'st'le and quarterdeck of ST. LAURENT derived destroyer escorts, forward of the bridge. Also mounted in X position on Tribal class DDEs, and A position on ALGONQUIN and aft on CRESCENT after the latter two's ASW conversions. BONAVENTURE carried four of these mountings when originally commissioned, but had the two forward mountings removed during her 1967 refit. Of the MACKENZIE class ships, QU'APPELLE carried a second of these mountings forward in place of the 3"/70 Mk.6 found on the rest of the class members.

The two PROTECTEUR class AOR's were originally fitted with this mounting on the foc'st'le, but its location exposed it to damage from heavy seas, and it was removed in 1984. The mountings were preserved ashore, and one was re-installed on PROTECTEUR for her deployment to the Persian Gulf in 1990-91.
The mounting was originally fitted with an SPG 34 tracking radar right on the mounting, which was later replaced with an SPG 48 tracker between the barrels (see photo 6). On NIPIGON and ANNAPOLIS, the SPG 48 and GUNAR fire control system was replaced with the Mk.69 GFCS and integral SPG 515 tracker during their DELEX refits."

and about the 3"/70:

"Mounted on the foc'st'le of destroyer escorts, forward of the bridge. This mount was originally developed for the RN for use in aircraft carriers, but was eventually installed in RN service only in the TIGER class cruisers, which mounted three mountings each (one forward, two amidships). This mounting experienced teething problems when entering service in RCN destroyer escorts, but these were eventually resolved. The ammunition handling system was apparently referred to as "the bottling plant" due to the high rate of fire achieved when working properly."

I came across some other information in my files on the 3"/70 that I thought I would post here. While originally marked CONFIDENTIAL and/or RESTRICTED, these documents were long ago declassified. I don't believe I have the entire document, but here is what I do have (hopefully they are legible) from either BRCN 1740 or CBCN 5902:

Page 1

Page 2

Page 3

A different cut-away view from a different document.

Page 4

Page 5

The only other Navy to use this gun was the Royal Navy on their TIGER class cruisers, TIGER, LION and BLAKE.

The forward 3"/70 on TIGER. M.D. Thomas photo.

Two more of these mountings (for a total of 3 per ship) were mounted port and starboard farther aft, though these mountings were eventually removed in favour of a new helicopter hangar.

A note about copyright: The pages of the document on the Vickers gun is hosted on my Smugmug website, and therefore displays my copyright watermark, but this document would originally have been copyright of the Crown.

HMCS IROQUOIS: Exterior Tour

To finish up the tour of IROQUOIS, I will walk through some of her exterior features and equipment. When the IROQUOIS class received the TRUMP refit in the 1990s, they were optimized for Air Warfare, but retained the Undersea Warfare capability originally fitted, and had limited Surface Warfare capability. Some of the photos here go back to the 1990s, and may have been taken on ATHABASKAN. My understanding of these systems is very basic, so my descriptions will not be very detailed. Which is probably just as well.

Undersea Warfare:

Designed as anti-submarine destroyers, IROQUOIS and her sisters were fitted with the latest in Canadian sonar equipment, originally the Computing Devices Canada (CDC) SQS-505 hull-mounted and variable depth sonars. These were later upgraded to the SQS-510 model. A number of years ago, I wrote an outline on RCN sonar systems here. 

SQS-510 Hull Outfit C3 sonar dome, removed for maintenance. The fairing itself is seen at bottom left, and is facing backwards.

Unlike the huge low-frequency bow-mounted sonar domes favoured by the US Navy and others, the RCN currently uses medium-frequency sonars in a smaller faired dome, situated just forward of the bridge. In previous classes, the sonar dome was originally designed to be retracted into the hull to reduce the ship's draft when entering port, but they were later fixed in the down position. I believe IROQUOIS was designed with the dome in a fixed position. This means that special care must be taken when dry docking these ships, to the extent that the graving dock at the Halifax Shipyard has wells cut into the bottom to accommodate the sonar dome and the propellers of these ships.

IROQUOIS also carried a second SQS-505/510 in a Variable Depth Sonar (VDS) system fitted at the stern.

SQS-510 towfish and launching gear. Note the faired cable that would lower the towfish to depth.

The VDS launching gear was installed in a cut-out in the transom. The operator worked behind the windows on the port side of the well, and the two ports on the starboard side are for the Nixie torpedo decoy.

The launching derrick would lift the towfish off its cradle, and pivot out over the stern to lower the towfish into the water. The towfish would be lowered to an appropriate depth via a faired cable, and would provide better detection abilities than the hull-mounted sonar as it would be not be affected by hull noise, and could be lowered below thermal layers that might mask the presence of a submarine.

Towfish being launched. Image courtesy of Corvus Publishing Group.

VDS was a Canadian Development in the 1950s, and was adopted by several other navies before being supplanted by towed array sonar systems such as the SQR-19 / CANTASS towed array sonar fitted to the HALIFAX class. The VDS was removed from the IROQUOIS class sometime in the first decade after 2000. 

VDS towfish cradle after removal of the VDS.

Once a submarine had been detected by sonar, Mk.46 lightweight torpedoes could be deployed against it from either the ship itself or a Sea King helicopter. 

Starboard Mk.32 triple torpedo launcher.

Unlike the fixed double Mk.32 launchers that fire at 45 degrees out the forward corners of the helicopter hangar on HALIFAX class frigates, the triple Mk.32 launcher on the destroyers was trainable and had to be directed out over the side. It is shown here in the stored position. Compressed air would be used to force the torpedo out of the tube and into the water, from where it would deploy its own motor and hunt for a target. 

Air droppable Mk.46 lightweight torpedo. A parachute is fitted in the cowling over the propeller nozzle.

The Mk.46 torpedo could also be carried by a Sea King helicopter, and air dropped with the help of a parachute that would detach when the torpedo hit the surface. These lightweight torpedoes are much smaller than the heavyweight ones carried by submarines.

Air Warfare:

Originally fitted for point-defence against aerial threats, the IROQUOIS class was refitted under TRUMP with area air defence systems that could extend an umbrella of protection to other ships operating in a task group, or to defend a convoy. First, all the radars were upgraded as part of that refit. (I have also written a summary of radars and fire control system used by the RCN over the years).

The main mast is bristling with sensors and other antennas.

Antennas for all of the primary air warfare sensors can be seen in the photo above. Looking from bottom to top, there is the port WM-25 Separate Target Illumination Radar (STIR), the LW-08 (AN/SPQ-502) long range air search radar, two navigation radars, and then the DA-08 (AN/SPQ 501) air/surface search radar antenna on the top of the main lattice mast. 

Port WM 25 STIR, with LW-08 in the background.

IROQUOIS carries two STIRs, port and starboard over the bridge. These would track and designate or "paint" targets for the ship's weapons systems, after being detected by the ship's other air defence radars. All the radars are gimbal-mounted to allow them to maintain a level disposition while at sea.

LW-08 long range air search radar

The LW-08 and DA-08 are the primary air defence radars, the former optimized for the long range detection of aerial targets, and the latter mounted higher on the main mast to provide better over-the-horizon aerial and surface detection. I believe the bar piggy-backed on top of each antenna dish is an Identification Friend or Foe (IFF) device. 

DA 08 air/surface search radar.

The primary air defence weapon is the Standard SM-2MR missile, deployed via a 29-cell Mk.41 vertical launch system (VLS). 

Mk.41 VLS.

Each cell of the 29-cell launcher can fit one SM-2 missile, or four RIM-162 Evolved Sea Sparrow Missiles (ESSM) in a quad-pack. Although the ESSM has now been added to the HALIFAX class ships in their Mk.48 VLS, I do not know if the IROQUOIS class has ever carried them. The launcher actually has room for 32 cells, but three cells are taken up by a strike-down crane (third row in, on the right of the photo above). This crane is apparently never used, and has been removed from later launchers in favour of three additional cells. In way of comparison, a USN BURKE class destroyer carries up to 3 of these launchers.

As an aside, the only vertical launched Sea Sparrow missiles that I am aware of ever being deployed from an IROQUOIS class ship was the 1981 testing of the Mk.48 VLS from HMCS HURON. I have seen a photo somewhere, as I recall showing two Mk.48 cells fixed to the side of the old Sea Sparrow launcher used by these ships pre-TRUMP.

Secondary air warfare defence is provided by both the OTO Melara 76mm gun, and the 20mm Phalanx Close-In Weapons System (CIWS). (Another version of this acronym that I have seen reads "Christ, It Won't Shoot"). 

Phalanx CIWS.

The Phalanx is a self-contained unit combining a 20mm gatling gun with a radar system, and is easily bolted onto ships that weren't necessarily designed to carry them. They are intended as a last ditch weapon to try and stop missiles ("leakers") missed by the primary missile system. The RCN retrofitted its Phalanx systems to the Block 1B standard, complete with the camera mounted on the side of the radome to help provide anti-surface capability.

IROQUOIS also carries four Plessey Shield flare and chaff launchers just aft of the bridge, and was also retrofitted with the Australian Nulka active missile decoy system.

Nulka launcher on the quarterdeck of ATHABASKAN in 2010.

Port Nulka launcher aft of the bridge of ATHABASKAN in 2010.

IROQUOIS can carry up to four Nulka launch cannisters, two port and starboard behind the bridge, and two side-by-side on the quarterdeck just aft of the helicopter deck. Nulka launches as a rocket from the cannister, but then can hover away from the ship and attempt to draw incoming missiles away from the ship. I was under the impression that the RCN did not buy enough units to fully equip all ships of the class, and would trade them off between the ships (on the East Coast at least).

Surface warfare:

Lacking dedicated anti-surface missiles like Harpoon (although I believe the SM-2 missile can be used against a surface target in a pinch), IROQUOIS relies primarily upon her 76mm gun and Phalanx CIWS (supplemented by .50 calibre machine guns for small surface craft). A summary of other gun systems used by the RCN over the years can be found here.

OTO Melara 76mm Super Rapid gun.

The Super Rapid version of the gun can fire 120 rounds per minute, and is improved over previous mountings to help counter anti-ship missiles as well as surface targets. The gun has a dedicated fire control system in the Lightweight Radar/Optronic Director (LIROD).

LIROD.

The LIROD is mounted between, and slightly forward of, the two STIRs.

This concludes, at least for now, my photo tours of IROQUOIS. I finish writing this just in time on April 25, 2015, less than one week before IROQUOIS pays off on May 1, after which 43 years of being "Relentless in Chase" will come to an end.