Today, mainline recertification trials were undertaken on former British Rail Class 55 "Deltic" 55 009 Alycidon, after the completion by its owners, the Deltic Preservation Society Ltd., of nearly four years of repairs to electrical damage cause by either contact with loosened overhead catenary or a lightning strike on a railtour/excursion on the West Coast Main Line on 3rd March 2019. The resultant high voltage power surge damaged the loco's #2 generator and all six traction motors of the fully freshly overhauled cast bogies that were being run in under her while her own fabricated bogies were awaiting repair. (It is my understanding that the lengthy and complex repairs were effected with a combination of insurance payouts, contributions, and volunteer labour.)

The loco is booked to operate on a main line excursion 13th May with UK Rail Tours, London Kings Cross to Scarborough and return, "The Coronation."

https://www.youtube.com/watch?v=bh6l5OfcaSo

Multiple other videos of the run are being uploaded to Facebook and YouTube seemingly each hour.

Image below, approaching Stafford today en route from Barrow Hill (a preserved roundhouse and motive power depot, where the DPS has its own loco shop/shed) to Carnforth on the WCML, by Sam Rogers.

Honorary ALCo?

Or a big brother to a Fairbanks-Morse OP engine, I understand the smoke from both is from burning lube oil rather than turbo lag as in an Alco.

Deltic: two-stroke opposed-piston with THREE crankshafts per engine. High power for weight but amazingly complex by RR standards. The characteristic "clag" is two-stroke engine smoke akin to an EMD 567/645 rather than GE and Alco engines. It's also been some years before she's blown the oil out of the silencers.................

Wait. Did they... Restore it and Run it On the Mainline?

All seven surviving Deltics, with the exception of 55.015 Tulyar, 55.016 Gordon Highlander (originally considered a "source of spares"!), and the English Electric prototype Deltic, have had some operation at high speed (up to 100 mph!) on the "main line" and various degrees of restoration since the retirement of the fleet by BR in January 1982. And Tulyar is still amidst a down-to-the-frame rebuild/resto that has been ongoing for years--a similar rebuild on Alycidon lasted from 1990 to 1998!.

The Deltic Preservation Society, which formed in 1977 and initially acquired 55.009 Alycidon and 55.019 Royal Highland Fusilier, also acquired the most "popular" of the fleet, 55.015, from a private owner in 1986. Two others, D9000/55.022 Royal Scots Grey and 55.016 Gordon Highlander, were acquired by a separate group, and have since passed through private hands a couple times. 55.022 was certified for main line operation but is currently down for repairs. It is the intent of the DPS to certify Tulyar for main line operation upon completion of its overhaul.

Even the National Railway Museum's 55.002 King's Own Yorkshire Light Infantry was restored to operation by volunteers and certified for mainline running at one point, but the NRM now views both it and the prototype as static exhibits only (ticking off the volunteers in the process).

To put in some perspective: The original BR Deltic fleet ran 20-22 years in service on the East Coast Main Line (former LNER Pacifics territory), and were retired largely because the HSTs replaced them and they just weren't a useful fit elsewhere. The preserved examples just marked, or are marking very shortly, the 40th anniversaries of acquisition from BR!

Are parts still available for those engines?

I read about them and consider them one additional counter-rotating crankshaft with 4 more pistons in a triangle more difficult to work on than an FM 38 8-1/8. Tolerances in timing must be a b***h to maintain.

When the units were retired, the DPS undertook even more fundraising to acquire every possible spare part it could muster--and that became seven spare power units (combination engine and generator bolted together), every possible spare they could muster, and even combing through Doncaster Works for such things as the unique fabricated jig created to lift the power units out for swap-out. It's taken several shipping containers and a support carriage to house them all over the decades. And the DPS has graciously loaned assistance and equipment as needed to the other operators.

The DPS also formed with several top officials from Napier and English Electric as board members and/or consultants. In addition, just as with F-M, Deltic engines found other applications,. most notably with the Royal Navy and its PTF "Nasty" patrol boats and the NYC Fire Department's unique Mack "Super Pumper" of 1965 (which still survives in Michigan, last I looked). I recall the DPS did undertake the recent acquisition of a spare Royal Navy engine for parts.

There's also a slightly allied project, a recreation of a BR Class 23 "Baby Deltic" with a single 9-cylinder Deltic engine (half the size of each of the two engines in a Class 55), being built around a cut-down frame of a Class 37 and the sole surviving T9-29 Deltic power unit used in the ten locos of the class. See https://www.babydeltic.co.uk/
In American terms, this would be akin to cobbling together a Fairbanks-Morse Erie-Built or Baldwin "Baby Face" around a sole surviving engine, or the colossal work undertaken to recreate the SP Krauss-Maffei diesel-hydraulic (which went as far as procuring the sole surviving trucks from a track machine in France!!).

A Deltic is a fascinating engine. Take three FM OP's and join them at the crankshafts. The engine will resemble the Greek letter Delta. Each bank has six pistons.

For its day it was the diesel with the best power to weight ratio. It was developed by the German Junkers firm in the 1930's as an aircraft diesel to give aircraft transatlantic range. The USA had achieved this with high compression engines burning high-octane gasoline, but this was not available to the Third Reich.

The aircraft with the Jumo diesels were not notable but Fairbanks-Morse adapted the design to US submarines where they were on a par with the Winton 201A and subsequent Cleveland 248 and 278A engines.

Napier took the design, connected them at the crankshafts and produced a very high horespower for its size diesel that required a great deal of maintenance.

The USN bought 20 Nasty class PTF Patrol boats with 2 Napier Deltic diesels each. [The WWII PT boats had aircraft-type gas engines. They burned spectacularly]

British Railways needed a high powered locomotive thay met their weight restrictions. Only a Deltic could do this so the BR Class 55 had two Deltic engines developing 3300 HP @ 1500 rpm.

And 100 mph sustained everyday speed. At 99 long tonnes (111 U.S./short tons).

So, Deltics were very much like a fast passenger Hudson in the steam era - designed for a very specific service and not easily adaptable for more general use, hence retired at the end of their service life for fast passenger service.

Also, definitely not a Tier IV prime mover!

A better metaphor might be an improved version of the Milwaukee A 4-4-2s (note how carefully I don't say "F7 Hudson") -- a locomotive depending on good acceleration and sustainable high-speed operation. Most of the American diesel-electrics capable of this performance would require two units to make this level of performance -- and aside from half of one of the PRR passenger Centipedes, which certainly doesn't qualify well as comparable high-speed power, the only thing comparable would have been an improved Ingalls Shipbuliding passenger unit (with the Bowes tugboat drive, and mechanical final drive)

It would have been interesting to see how single-engine passenger power would have evolved in the United States had demand for lightweight high-horsepower high-speed power not been abbreviated by the Naperville wreck and its consequences. The possibilities of a Speed Merchant-type locomotive, for example, capable of working with actual trains instead of 'lightweight trains of the future' would be interesting; the LRC locomotive is an indication of what was achievable with an Alco 251. There was also the promise of free-piston power (which imho is why Lima merged with Hamilton, and then Baldwin merged with Lima-Hamilton with the connivance of Westinghouse) but ... in the absence of a specific demand for that type of power -- found its evolution as, for example, the CG9, decidedly back-burner.

I respect the accomplishment in returning an obsolete diesel to service (In many ways diesels are way more difficult to restore than steam engines.). But when acquiring parts, it's too bad that they couldn't acquire an E8 body from the US. Purely my opinion, but that is one butt-ugly diesel!

The Australians got something very right when they built a series of road locomotives with EMD cowl-style carbody ... but avoiding the Frankenstein-style contemporary EMD wide-nose cab...

The initial problem with the E8 nose it that it would have to be cut down to fit the British loading gage. This might leave it distressingly simpliar to a Baldwin Babyface nose... NOT the answer even in chronically-butt-ugly-nose Britain.

The second problem is that the square nose is probably packed with various components that can't easily be fitted elsewhere in the carbody, or in a more svelte phiz. I'd think that something like the prow of the Baldwin Essl demonstrator might be used...

... but a far better one would be a scaled version of the Baldwin Sharknose, which of corse goes with the lovely 'windscreen' on the Deltics. This wouldn't have to be the flattened and tiny adaptation used on Train X, either. Perhaps strange to mention, I'm actually waiting for the next slated 'revival' of the old Miracle Castings BP-20 shell to put a couple of these noses on an (admittedly slightly larger-scale) Deltic to see what it would have involved... ;-}

Left out of the above speculation is the fact that, at its construction, the Deltic prototype was the most powerful single-unit diesel loco in the world, and its performance was on the order of world-record-setting at the time. The prototype was set up with headlights for export as a demonstrator to North America and elsewhere, but that never transpired, in part because Napier and EE recognized that North American railroading suffered from extreme ethnocentrism and "Not-Invented-Here-Phobia." Even the Amtrak "Swedish Meatballs" had to be built here by EMD to find acceptance.

There were serious efforts to find a new duty for the Deltic fleet when the HSTs replaced them on the ECML, such as expanded operations to cities off the ECML where HSTs weren't penetrating yet, like Derby/Leeds, Sheffield, and Hull, or even Cambridge/Kings Lynn, but ultimately the specialized nature of the beasts compared with the then-ubiquitous Class 47 mandated their premature retirement.

Railfan & Railroad editor Jim Boyd, when he found out I not only knew about Deltics but was a DPS member, once picked my brain about who might have tested a Deltic demonstrator, had it shown up in 1959. We disregarded the perilous state of passenger rail in North America at the time, and my mind immediately went to who had 100-mph trackage--Milwaukee, Burlington, ATSF............... Then Jim said, "C'mon! The Pennsy bought one of EVERYTHING!!!" He envisioned a lineup of GG1, EMD E7, and a Tuscan red Deltic at South Amboy, and was supposedly looking for an artist to create such an image at one point before his passing..........