Reddit mentions of Royal Navy Type 45 Destroyer Manual - 2010 onward: An insight into operating and maintaining the Royal Navy's largest and most powerful air defence destroyer (Owners' Workshop Manual)

Power

>Type 45 travels at a top speed of 32 knots to AB's 30

At what loading? And what suggests that the Burke is limited to 30 kts?

The Zumwalt, for instance, was spec'd to only 30 knots or so but did 33.5 in trials on what looked like a light load. (Also, Zumwalt displaces 40-50% more than Burkes, produces the same 78 MW_shaft, but can still do 33.5 knots. It stands that the much lighter Burke could go faster on the same power (assuming similar admiralty coeffs).)

>Type 45 uses IEP and a combined diesel-electric-gas setup so its shp is difficult to determine and there aren't many sources on it, though it should be a power of 50-60kW+

How are the Daring's engines geared to the shafts? Is it mechanical? Or electric-only? If electric-only, then regardless of total GT+diesel power, the shaft power is limited by the motors, which are 20 MW each. It appears only the electric motors are physically coupled to the props, so total shaft power should be 40 MW. The 2x 2MW diesel alternators don't contribute to shp unless the GTs are operating below capacity/damaged/off. And while the GTs are rated 25 MW each, their associated alternators are only rated to output 21 MW each.

So while total power is 54 MW, only 46 MWe is generated, and only 40 MW is delivered to the shaft. So Burkes still get ~2x shp.

https://www.amazon.co.uk/Royal-Navy-Type-Destroyer-Manual/dp/0857332406

>the AB's 70-80kW

Burkes produce 78 MW_brake. Plus an additional 7.5 MWe of diesel generators on top of that (not available for propulsion obviously).

>Type 45 is also due an upgrade in this regard, adding a third engine

That would be very unusual. I don't recall that being done before. And I don't think the design could accommodate it. GTs have a large footprint (especially the intakes/uptakes) in the coveted heart of the ship where virtually all the volume is already spoken for. They're very tightly integrated into the ship with their gearing, shafts, shock mounts, light armor, careful arrangements to facilitate maintenance and minimize power/propulsion loss (eg multi-engine) in various damage cases (IEP makes arrangements more flexible, but there's still electrical distribution). The voluminous intakes/uptakes run practically from the very bottom of the ship to the very top. To carve out room for a third GT, you'd have to relocate a lot of important stuff from aux machine rooms, to damage control stations, the CIC, the radars, topside launchers, w/e.

To be affordable, you'd have to design it for but not with a third engine. But installing one is not painless. Just replacing existing engines isn't supposed to happen until a major overhaul/upgrade (or if it takes damage, see: DDG-1001) and often includes cutting huge holes in the ship (although I believe some are designed to be lifted out through the stack). But making provisions for a third engine without installing said engine isn't cost effective either. An LM2500+G4 costs just $10-20 million. The concomitant design changes will cost several times that. If you want to save money/fuel/maintenance, install a third engine from the outset, just don't turn it on. That's apparently how the Type 45 was envisioned to use its second GT+diesel most of the time anyway.

So unless you designed the ship for-but-not-with a third GT, it'd be ruinously expensive to add it after-the-fact. It'd be easier to splice in a hull insertion. You'd need to find some crippling design flaw to justify that kind of drastic modification.

So that's why you piqued my interest with "third engine!" Thankfully, I don't think such a calamity occurred. It looks like they're just replacing the old/current 2x 2MW diesel generators with new 3x 2MW diesel generators. https://www.rina.org.uk/Type_45_to_get_third_diesel_generator_to_overcome_problems.html That articles includes more background on IEP issues and continuing work. TLDR: teething issues, insufficient funds for testing

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AAW

>the [Sylver VLS] design is one-deck-level-deep, allowing them to be individually expanded where necessary

Are you sure? The total launcher is 6m tall. The 5m cell alone would be a pretty tall deck, even with 1-2 m protruding above 1-Deck. The A50s look like they span two decks (2-Deck and 3-Deck), right down to the waterline (which is better for CG anyway).

>it currently has 48 SYLVER silos, it is designed to go up to 64

I didn't know that. To the wiki!

"There is provision for another 12[74][84] strike-length VLS tubes forward of the existing VLS. These could be Mk 41 tubes for Tomahawk land-attack cruise missiles (TLAM) and LRASM, or Sylver A70 for the MdCN derivative of Storm Shadow." 84: "Early in the design phase it was estimated that 16 strike-length tubes could be fitted and this number has been widely circulated, but as of 2010 the RN website said 12."

>There is also the capability to easily replace them with the more versatile LM Mk41s

I think that's just in reference to the 12 cells yet to be fitted, rather than replacing current Sylver A50 cells.

>The RN believes in multi-layered AAW, prioritising tracking at longer ranges and interception at mid-close ranges with a one-shot-one-kill policy, as this is what has been shown to be the most effective, a lesson partly learnt from the Falklands War. This is why the long-range interception capabilities and slightly fewer missiles are not so important, as it does not abide by RN philosophy.

Let's take that at face value for sake of argument. By the same token, if you run a Burke on the same SLS shot doctrine, you'd get 2-3x the kills because it has (at least) 2-3x the interceptors. You could argue that the Type 45s get better Pks, but probably not 2-3x better or near-perfect (that'd be difficult to substantiate for or against anyway).

Also, SLS is very difficult unless you have either a) supreme interceptor Pks or b) very reliable/capable local+point defenses and soft-kill systems to chase down leakers. I don't know anything about RN defensive EW, but I don't think you should rely on 2x Phalanx. The RIM-116 upgrade you mentioned would help, though I didn't find any concrete plans of it going through yet.

SLS is possible though. The USN itself is moving towards a single-layer, medium-range based defense (rather than multilayered from long- to short-range). But USN includes more than just Phalanx: a) lasers, railguns, and EW to stop leakers (TTT ~0) and to augment medium-range defense, b) SSLS for the time being, and c) a long-range, OTH, offensive AAW effort. Which leads me to…

>This is why the long-range interception capabilities… are not so important, as it does not abide by RN philosophy.

Offensive AAW is important for thinning out the archers before they launch their payloads. The Chinese H-6 can carry 6 AShMs, the B-1B can carry 24, and Soviet Naval Aviation is in/famous for its Backfire regiments armed with Kh-22s. An unmolested strike package (flown by a near-peer) has a sporting chance of saturating your defenses, especially if you magazines are shallow. Even if commanding a CBG in the 80s, you did not want to let your adversary release all their missiles, then wait until "mid-close ranges" to shoot down each and every missile:

They [Soviets] roughly had a Regiment per [our USN] carrier. In a straight-forward engagement, the issue would have been "in doubt" at best. If a strike regiment caught a CV by surprise it would have been curtains. An alerted CV would have a better than even chance of surviving, but probable losses would have been severe. But the Regiment running through fighter opposition to their launch points and then getting back out would have taken crippling losses. They would have not been able to mount a second strike and would have been effectively destroyed if not annihilated. If a missile trap is set so that the regiment is climbing to launch altitude over a missile ship it doesn't know about until the radar comes up and missiles start impacting, the fight will be over before it barely starts. So it was critical for the target to be identified and located prior to the regiment being committed. How to Hide a Task Force http://www.navweaps.com/index_tech/tech-031.php

Arguably the RN may never require its forces to be capable of standing against a peer/near-peer's air force (eg just another Argentina), and that's fine (maybe), but we're talking about the "best" AAW destroyer, aren't we? :P

>long-range interception

Affords your escortee maneuvering room (eg deception), less tightly glued to escorts.

> slightly fewer missiles are not so important, as it does not abide by RN philosophy.

Not slightly more. A Burke can host multiple times more SAMs. Realistically about 2-3x more, with cells to spare for other missions, or up to 8x more in an impractical/unlikely loadout (all ESSMs).

>the USN, as it can afford to have more of everything where the RN needs a few ships to do the jobs of many

A Burke sounds great for the RN then :P Better than that single-job Daring, eh? Eh?

Eh. The USN also takes on a lot more missions and is spread pretty thin (three collisions in a couple of months, holy moly). The USN is a bit top-heavy with very capable multi-mission destroyers/cruisers than can "do the jobs of many." But without a lot of smaller assets (like OHPs, corvettes, ESB/MLP/AFSB/ESDs) to pick up constabulary missions, our 10,000 ton ships are stuck doing antipiracy without time for proper mx or training for the high-end fight (like ASW).