Tirpitz and Graf Zeppelin 1941

[dunmunro]

The Ar-196 was clearly superior to the Albacore, but in fact they did not score any kills, but two Albacores were lost from Flak. Air combat in conditions of low ceiling and cloud tends to favour the defender, as it makes it easier to withdraw from unfavourable tactical situations. However, if Fulmars had been present, they would probably have shot the Ar-196s down unless they too fled into the cloud. OTOH, if Fulmars had encountered 109Ts the Fulmars could have also fled into the cloud.

[srgt rock]

I think the posts relating the relative merits of Fulmar and 109T gives the energy availability to the 109T so German dogfight tactics will be climbing and diving and generally give them the ability to achieve the all important higher altitude most of the time. I will also grant that the AW radar carried by both Carrier Task Forces will allow their CAP fighters to be in a tactically favorable position.

So now to set the date of Operation Rapier.

I assume the air ops the Germans conducted during the air support phase of Operation Albion2 allowed the German Carrier CAG to develop improved air operations plans to best suite GZs capabilities. All ships planned for Rapier have undergone refits and continued training following the conclusion of Albion2. British PRU units will appraise Admiralty of this fact.

The trigger: Ark Royal has just sunk during Operation Perpetual. Raeder convinces Hitler to roll the dice. German forces sortie 21 Nov 41. German ships WILL NOT travel through the Kattagat as BS & PE plus Lutzow were spotted there by the allied intelligence networks. Admiralty has a good idea what the Germans plan to try but not the operational details.

If the British can locate the Northern Battle Group as it passes Norway, the combination of AW radar guided CAP and shipboard flak prevent the German ships from suffering enough damage to stop them. The Northern Battle Group refuels and is ready to attempt breakout by 28 Nov 41.

As the Germans are rolling the dice, land based recon will blanket the Iceland-Faroes Gap to provide the number and approximate location of any British surface units. There will also be a double line of U-boats stationed there to provide sighting reports and maybe attack any British Naval units they encounter.

As the Admiral commanding Rapier's forces, I will group the Carrier Task Force with the Surface Strike Force and I will also grab the S-boats from the Support Group. The remaining Support Group ships will follow behind. I will not attack the British Carriers only the ships on patrol in the gap. I would keep the bulk of my fighters to use as CAP. The strikes against patrol ships will have minimal, if any, fighter escort. I might be sighted but not for long and I will use my speed to avoid surface units. I think I stand a better than average chance of a successful breakout.

What would Admiralty do? Have the Germans already affected the North Atlantic convoys just by sortieing?

[delcyros]

Thanks for providing the data on the Fulmar, D.

My specs for this plane refer to:

Fairey Fulmar Mk.I
Engine: Rolls Royce Merlin VIII
Power: 1,080hp from sea level to 1,000ft
Crew: 2
Wing span: 47ft 4in
Length: 40ft 2in
Height: 11ft 6in (tail down)
Empty Weight: 6,915lb
Maximum loaded weight: 10,700lb
Max Speed: 265mph at 7,500ft, 230mph at sea level
Service Ceiling: 21,500ft
Endurance: 4 hours with combat reserves
Armament: Eight .303in machine guns, eight 20lb or 25lb anti-personnel bombs

Fairey Fulmar Mk II
Engine: Rolls Royce Merlin 30
Power: 1,300hp from sea level to 1,000ft
Crew: 2
Wing span: 47ft 4in
Length: 40ft 2in
Height: 11ft 6in
Empty Weight: 8,650lb
Maximum loaded weight: 10,350lb
Max Speed: 266mph at 9,600ft; 259mph at 9,000ft; 245mph at 15,000ft
Cruising Speed:
Service Ceiling:
Endurance: 5 hour 30 minutes with combat reserves
Armament: Eight .303in machine guns or four .50in machine guns
Bomb-load: Eight 20-25lb bombs or one 500lb bomb under fuselage

http://www.historyofwar.org/articles/we ... ulmar.html

Different stats are likely to occur. A scatter of data has to be reckoned with, reflecting individual differences in performance. The Fulmar Mk1 was in production to 1942 when it was replaced by the mk2. The Fulmar mk2 didn´t appeared in service before the start of 1943.
I can´t really see how that plane is a match for the Bf-109T. I have seen a couple of engagement reports where even Ju-87B jettisoned their bombs and entered in aerial dogfight with the Fulmar, in some cases with success. The difference between Ju-87 and Fulmar mk1 in performance is about as large as the difference between Sea-Hurricane Ib and Bf-109T. The Ju-87 is at some disadvantage (as is the Sea-Hurricane against the Messerschmidt) but it´s still competetive enough to make up for a fight. However, the difference between Bf-109T and Fulmar (regardless which mark) is exceeding what can be framed as "competetive".
I don´t think that the F4F and A6M example is outlining this. F4F (315mp/h) and A6M (332mp/h)are somehow competetive as demonstrated by Lundstrom and Blutarski above -under certain conditions. Their performance gap is not to large. I just fail to see under which conditions the Fulmar is competetive with the 70 mp/h to 80 mp/h faster Bf-109T. The Fulmar is significantly inferior in every single performance aspect You look at. It can´t outrun, it can´t outdive, outturn or outclimb it´s opponent. The Fulmar would have been good to deal with Ju-87 and Fi-167 but it had to be rather careful, avoiding a turning fight with them and concentrate on the vertical.

285mp/h with +12lbs boost is quite a feature on the deck for the Sea-Hurricane. Higher boost would be aviable from mid 1942 on (at this time you have to reckon with Db601E in Bf-109´s). That´s probably competetive enough, given that the Hurricane can at least turn (but neither accelerate, climb or dive) with the Bf-109T.

[dunmunro]

GZ will be trying to carry out flight operations in Northern waters noted their extremely bad weather, and in late November, almost perpetual darkness. These are conditions which favour surface raiders but which make flight operations extremely difficult (almost impossible, actually) in the absence of ASV radar.

I would like to see some details on KM AW radar, since there is no evidence such radar was in existence in Dec 1941.

[dunmunro]

Thanks for providing the data on the Fulmar, D.

My specs for this plane refer to:

Fairey Fulmar Mk.I
Engine: Rolls Royce Merlin VIII
Power: 1,080hp from sea level to 1,000ft
Crew: 2
Wing span: 47ft 4in
Length: 40ft 2in
Height: 11ft 6in (tail down)
Empty Weight: 6,915lb
Maximum loaded weight: 10,700lb
Max Speed: 265mph at 7,500ft, 230mph at sea level
Service Ceiling: 21,500ft
Endurance: 4 hours with combat reserves
Armament: Eight .303in machine guns, eight 20lb or 25lb anti-personnel bombs

Fairey Fulmar Mk II
Engine: Rolls Royce Merlin 30
Power: 1,300hp from sea level to 1,000ft
Crew: 2
Wing span: 47ft 4in
Length: 40ft 2in
Height: 11ft 6in
Empty Weight: 8,650lb
Maximum loaded weight: 10,350lb
Max Speed: 266mph at 9,600ft; 259mph at 9,000ft; 245mph at 15,000ft
Cruising Speed:
Service Ceiling:
Endurance: 5 hour 30 minutes with combat reserves
Armament: Eight .303in machine guns or four .50in machine guns
Bomb-load: Eight 20-25lb bombs or one 500lb bomb under fuselage

http://www.historyofwar.org/articles/we ... ulmar.html

Different stats are likely to occur. A scatter of data has to be reckoned with, reflecting individual differences in performance. The Fulmar Mk1 was in production to 1942 when it was replaced by the mk2. The Fulmar mk2 didn´t appeared in service before the start of 1943.
I can´t really see how that plane is a match for the Bf-109T. I have seen a couple of engagement reports where even Ju-87B jettisoned their bombs and entered in aerial dogfight with the Fulmar, in some cases with success. The difference between Ju-87 and Fulmar mk1 in performance is about as large as the difference between Sea-Hurricane Ib and Bf-109T. The Ju-87 is at some disadvantage (as is the Sea-Hurricane against the Messerschmidt) but it´s still competetive enough to make up for a fight. However, the difference between Bf-109T and Fulmar (regardless which mark) is exceeding what can be framed as "competetive".
I don´t think that the F4F and A6M example is outlining this. F4F (315mp/h) and A6M (332mp/h)are somehow competetive as demonstrated by Lundstrom and Blutarski above -under certain conditions. Their performance gap is not to large. I just fail to see under which conditions the Fulmar is competetive with the 70 mp/h to 80 mp/h faster Bf-109T. The Fulmar is significantly inferior in every single performance aspect You look at. It can´t outrun, it can´t outdive, outturn or outclimb it´s opponent. The Fulmar would have been good to deal with Ju-87 and Fi-167 but it had to be rather careful, avoiding a turning fight with them and concentrate on the vertical.

285mp/h with +12lbs boost is quite a feature on the deck for the Sea-Hurricane. Higher boost would be aviable from mid 1942 on (at this time you have to reckon with Db601E in Bf-109´s). That´s probably competetive enough, given that the Hurricane can at least turn (but neither accelerate, climb or dive) with the Bf-109T.

The Fulmar 1 was in production from April 1940 to Dec 1940 and 160 were built. Fulmar II fully replaced Fulmar I production from Jan 1941 onward and ~450 were built. Fulmar II N4017 was the first Fulmar II production aircraft and it was delivered in December 1940. The first 100 Fulmar IIs were delivered by April 1941 . (See Sturtivant, Fleet Air Arm Aircraft 1939-45, for all FAA aircraft production by type and date of delivery for each aircraft along with a brief service summary of each aircraft)

From your stats:
Fulmar I
Empty Weight: 6,915lb
Fulmar II
Empty Weight: 8,650lb

The Fulmar II is lighter than the Fulmar I, not the other way around!

The Merlin VIII had its power rating revised as 100 octane fuel was used exclusively for combat units.
The performance data that I provided is taken from RAE test reports.

The Me109T is not 70 to 80 mph faster than an Fulmar II although ~50 mph is still a considerable advantage. Carrier modified 109Ts will be heavier and slightly slower than the aircraft you describe. However, consider the following: A Fulmar II weighs 9850lb with 155ig of fuel, 2 crew and 8000 rounds of ammo. The performance data is given for this weight, however the same aircraft in combat with 1/2 fuel, 1/2 ammo and no observer will weigh about 1200lbs less or 1000lb less with the observer (the Fulmar was occasionally flown as a fighter-interceptor without the rear observer) and it's performance will increase dramatically as a result.

The combat between the Ar 196 and the Albacore would an interesting analogy between the Fulmar and 109T, but in conditions of poor visibility and low ceiling the single seat 109T would actually be at a disadvantage over a two seat Fulmar. Situational awareness is critical in aircombat!

Again, the Fulmar faced SE and TE fighters on several occasions and acquitted itself well, and although the FAA admitted that it preferred not to engage SE fighters with the Fulmar, the actual combat stats prove that it was not an easy kill and could destroy enemy fighters easily, if the opportunity presented itself. However the Fulmar was not the only fighter in the FAA inventory. The combat over Kirkenes highly favoured the Luftwaffe fighters because it was almost perfectly clear with no clouds, but the Fulmar's did not get annihilated.

I don´t think that the F4F and A6M example is outlining this. F4F (315mp/h) and A6M (332mp/h)

These speed are achieved at ~20000ft! No one is going to be fighting over the North Atlantic in Nov-Dec 1941 at 20000ft! At SL the maximum speed of the F4F-4/A6M-2 is ~270-280 mph or only about 20-30 mph faster then the Fulmar. At kirkenes almost all combat took place under 9000ft and under 10000ft the Fulmar II can outclimb a F4F-4 and is only 20-30mph slower.

Fulmar external stores:

[delcyros]

The aircraft I referred to above is the navalised, carrier modified Bf-109T1 according to the Datenblatt of that airplane. Not the Bf-109E.
The -E4/N with Db-601N and 100oct. fuel had a speed of 500 km/h at sea level and 5 min rating (= 311 mp/h). That´s a considerable 16 mp/h faster on the deck than the Bf-109T-1. At 2800rpm Kurzleistung speed improves to ~310 mp/h for the T-1 at sea level (about the same as the E4/N with 5min power). Kurzleistung is cleared for in late 1941. Top speed of the T-1 is reported with 357 mp/h at 5,300m, altough I guess you will find different figures +-3%, reflecting individual performances and the influence of rammed air compression.
The original first seven pre-serial T-0 had no centerline ETC (only -T´s to not have it) and were in clean fighter configuration, but all seven T-1 and the T-2, both of which were based on the Bf-109E7/N with ETC-501 centerline rack were rebuildt to carrier standarts of the previous T-1, the ETC of the T2 was not removed, so these planes, except for the pre-serials could carry either a single 250kg bomb or a drop tank.
A 250kg bomb reduced the speed at sea level by 14 mp/h, an 300ltr drop tank by 12 mp/h, the ETC without bomb or drop tank by 3 mp/h, guessing from later trials with -G1, G-2, G-4 and G6. These correction are not applied for in the data referred to above (Bf-109T0).

I don´t think the Sea-Hurricane in it´s fully navalised Ib version with arrestor hooks, catapult spools and structural reinforcements is as fast as the unnavalised Hurricane I, either. The latter achieved 285mp/h at Sealevel with +12lbs boost. The heavier and more draggy Sea-Hurricane Ib is a bit slower, too. AT least that´s what I suspect.

As mentioned before, top end speed is of secondary importance. Cruise speed is more telling as it allows for an initial energy advantage independent of altitude. Acceleration is much more important, too as it exposes how energy may be stored in climb and regained after turns.
2850kg is the most commonly cited MTOW of the Bf-109T, which results in a powerweight of 0.412, which is massively superior to other naval fighters.

[Pandora]

after reading your last posts I conclude that:
in theory in dogfights the ranking would be

1. M-109
2. Sea Hurricane
3. Fulmar
4. Stuka
5. Arado 196
6. Fieseler 167
7. Albacore
8. Swordfish

do you agree?

[delcyros]

No. A ranking shouldn´t be attempted.
Aerial warfare is very different to naval warfare and tactics as well as teamwork are to determinant factors to be nelected.
Airplanes are- by all measure- fragile instruments.

[Pandora]

that is why I said "in theory".
for example, in theory, a Fulmar is superior to a Fieseler in a dogfight, but it doesnt guarantee it would be victorious all the time.

[delcyros]

This is very problematical. Take the example Fulmar vs Fi-167.

According to the Fumar´s pilot notes (Air publication 1760a, volume I, revised april 1942, issued with A./L. 21D) for both, Fulmar 1 and mk2, the engine was cleared for +5.25lbs operating with 87cot fuel and +9.0lbs boost using 100oct fuel in mid 1942 (only during take off or very low altitude).The Fulmar mk2 could operate +12.5lbs boost at take off and +9.75lbs at WEP (5 min).
The Fulmar mk2´s SL speed is given with 215kts at WEP(+9,75lbs), 233kts at 6600ft (crit altitude), 223kts at 11,600ft. Similar speeds for the Fi-167 are 175kts (325km/h) at SL and 187kts (347km/h) at 11,480ft (crit altitude).
The FULMAR has a very clear advantage in top end speed by a margin of 40kts at sea level. That´s considerable enough to be attributed as a "significant advantage".
But what about encounter conditions? The Fieseler cruises at 146kts (270 km/h)- a slightly higher speed than the suggested range of cruise speeds given in the Fulmar´s pilot notes (105kts for max andurance and 130kts for max range) and it´s climb rate with 2,440fps at Kampf-und Steigleistung (30min rating) can only be beaten with +9.75lbs boost (5 min) in the fulmar mk2, else it has a +1000fps climb advantage over the Fulmar. With the bombs jettisoned, both planes can engage aerobatics, their acceleration is similar but all maneuverability related questions favour the Fieseler. It´s total flying enevelope isn´t smaller, even though top speed is slower. That is a result of it´s extremely low stall figure (32kts), about half as low as the Fulmar´s.

Outclimb and zoom-climb is very complicated by the fact that the max. climb rate is reached at only 110kts in the Fulmar, which is well inside the Fieseler´s climb enevelope for this speed. Outclimbing is a no go and turning with the Fieseler only allows the latter to get a clean deflection shot or else, in case the Fulmar starts from an advantageous position, allowing the Fieseler´s rear gunner to get a deflection shot. Entering a prolonged turnfight is suicide. The Fulmar is forced to utilize it´s advantages in a different way. Pulling away horizontally exploiting it´s higher end speed, but this takes time and the acceleration difference is only noteworthy when the Fieseler slowly approaches it´s own end speed. The Fulmar is at a general advantage if it dives away (reaching the end speed quicker), where the Fieseler cannot follow the Fulmar. Diving is probably not always an option at low altitude. Energy management is very important for the Fulmar because high speed and a powerful forward battery are the Fulmar´s advantages over the Fieseler.
Energywise the Fulmar may even start from a disadvantageous position when cruising at what the pilot notes of this plane suggested in terms of cruise speed.


Tactics and cooperation are required and that´s hardly as quantifyable as technical details.

[srgt rock]

GZ will be trying to carry out flight operations in Northern waters noted their extremely bad weather, and in late November, almost perpetual darkness. These are conditions which favour surface raiders but which make flight operations extremely difficult (almost impossible, actually) in the absence of ASV radar.

I would like to see some details on KM AW radar, since there is no evidence such radar was in existence in Dec 1941.

First of all, flight ops would be extremely limited, if at all in the refueling zone. (I would conduct none.) As stated in my op plan, breakout would be in GOOD WEATHER. That lessens the British advantage in radar. Flight operations would be limited even during the approach to the Iceland-Faroes Gap. Land based planes will be searching the region of the gap. The Battle Group need only recon the exact route they plan to use. CAP would be minimal but I would have fighters fueled and on deck, ready for a rolling take off to reinforce the CAP when needed. The amount of daylight increases as the Northern Battle Group moves south.

Another point to ponder. Up to now, all German breakout attempts have been during BAD WEATHER. Would the British admirals expect a GOOD WEATHER attempt? Would they perhaps be dispersed because of refueling?

As for the KM AW radar, I'm working on that.

I will try today to put together a list of British cruisers that were in home waters in Nov 41. Argus needs to be added to the British force availability table.

[dunmunro]

This is very problematical. Take the example Fulmar vs Fi-167.

According to the Fumar´s pilot notes (Air publication 1760a, volume I, revised april 1942, issued with A./L. 21D) for both, Fulmar 1 and mk2, the engine was cleared for +5.25lbs operating with 87cot fuel and +9.0lbs boost using 100oct fuel in mid 1942 (only during take off or very low altitude).The Fulmar mk2 could operate +12.5lbs boost at take off and +9.75lbs at WEP (5 min).
The Fulmar mk2´s SL speed is given with 215kts at WEP(+9,75lbs), 233kts at 6600ft (crit altitude), 223kts at 11,600ft. Similar speeds for the Fi-167 are 175kts (325km/h) at SL and 187kts (347km/h) at 11,480ft (crit altitude).
The FULMAR has a very clear advantage in top end speed by a margin of 40kts at sea level. That´s considerable enough to be attributed as a "significant advantage".
But what about encounter conditions? The Fieseler cruises at 146kts (270 km/h)- a slightly higher speed than the suggested range of cruise speeds given in the Fulmar´s pilot notes (105kts for max andurance and 130kts for max range) and it´s climb rate with 2,440fps at Kampf-und Steigleistung (30min rating) can only be beaten with +9.75lbs boost (5 min) in the fulmar mk2, else it has a +1000fps climb advantage over the Fulmar. With the bombs jettisoned, both planes can engage aerobatics, their acceleration is similar but all maneuverability related questions favour the Fieseler. It´s total flying enevelope isn´t smaller, even though top speed is slower. That is a result of it´s extremely low stall figure (32kts), about half as low as the Fulmar´s.

Outclimb and zoom-climb is very complicated by the fact that the max. climb rate is reached at only 110kts in the Fulmar, which is well inside the Fieseler´s climb enevelope for this speed. Outclimbing is a no go and turning with the Fieseler only allows the latter to get a clean deflection shot or else, in case the Fulmar starts from an advantageous position, allowing the Fieseler´s rear gunner to get a deflection shot. Entering a prolonged turnfight is suicide. The Fulmar is forced to utilize it´s advantages in a different way. Pulling away horizontally exploiting it´s higher end speed, but this takes time and the acceleration difference is only noteworthy when the Fieseler slowly approaches it´s own end speed. The Fulmar is at a general advantage if it dives away (reaching the end speed quicker), where the Fieseler cannot follow the Fulmar. Diving is probably not always an option at low altitude. Energy management is very important for the Fulmar because high speed and a powerful forward battery are the Fulmar´s advantages over the Fieseler.
Energywise the Fulmar may even start from a disadvantageous position when cruising at what the pilot notes of this plane suggested in terms of cruise speed.


Tactics and cooperation are required and that´s hardly as quantifyable as technical details.

The Fulmar I never operated with 87 octane fuel in combat and the manual states:
"Operational units 100 octane, other units 87 octane or higher". Both engines were combat approved for full boost (9/12 lbs) at any altitude and 3000rpm and the manual states:

(merlin VIII)(vi) Boost Control cut-out. When 100 octane fuel is used a maximum boast of +9 lb/in. in. may be obtained for TO by operating the boost control cut-out.

Additional power at low altitudes may also be obtained in the same manner when necessary in operations but all such occasions must be reported and an entry made in the engine log book.

(Merlin 30)(Vii) Boost control cut-out.

Increased power can be obtained when operating conditions necessitate it by operating the boost control cut-out With the throttle opened to (not through) the gates All such occasions must be reported and an enter made in the engine log book.

but being low altitude rated engines, full boost could only be obtained up to ~9000ft/6000ft for the I/II. The Barracuda I/II manual gives a better explanation of Merlin XXX engines limits:

(iv. Combat concession.— +12 Ib./sq. in. emergency boost (fully effective up to 6,ooo ft.) can be obtained by operating the boost control cut-out with the throttle opened as far as the gate. Use of this concession must be reported and an entry made in the engine log book.

Regarding cruising speed, the speeds given for the Fulmar in the manual are in IAS but those for the Fi-167 are probably TAS at its most favourable altitude. At 15000ft, the IAS cruise for a Fulmar is 130 knots = ~169 knots TAS. The Fi-167 speeds are also given at optimum altitude, and with a bomb load it's speed and climb rate will fall further.

In any event it seems that the Ju-87B would be a more likely opponent.

[dunmunro]

First of all, flight ops would be extremely limited...

Good weather conditions in a North Atlantic winter will be extremely limited, and navigation for KM aircraft at night/bad weather will be hazardous in the extreme. The FAA found that only the Albacore/Swordfish could operate in severe but typical winter sea states, and this was from much larger carriers than GZ. Obviously, as the sea state worsens the Fulmar/Sea Hurricane with their more rugged LG will have a considerable advantage over the 109T in carrier flight deck operations.

I think we are gaining a clearer picture as to why the KM never completed the GZ.

[paulcadogan]

The FAA found that only the Albacore/Swordfish could operate in severe but typical winter sea states, and this was from much larger carriers than GZ.

Larger carriers? Not in the RN....GZ would have been much larger than British WW2 carriers - 27,000 tons, 860 feet long - Ark Royal was 800 ft, Illustrious 740. Maybe you're thinking of the planned Hipper-class conversion (Seydlitz)?

Wasn't it their biplane status that would make the Swordfish/Albacores more flyable in bad weather?

[dunmunro]

The FAA found that only the Albacore/Swordfish could operate in severe but typical winter sea states, and this was from much larger carriers than GZ.

Larger carriers? Not in the RN....GZ would have been much larger than British WW2 carriers - 27,000 tons, 860 feet long - Ark Royal was 800 ft, Illustrious 740. Maybe you're thinking of the planned Hipper-class conversion (Seydlitz)?

Wasn't it their biplane status that would make the Swordfish/Albacores more flyable in bad weather?

oops, yes, I was looking at the stats for a smaller conversion. Whitely states a standard displacement of 23,200mt for GZ although this was probably a moving target, as it were. Whitely also states an 820/88.6 ft L/B. Apparently the ship's dimensions changed after 1942:

The Graf Zeppelins' original length-to-beam ratio was 9.26:1, resulting in a slender silhouette. However, in May 1942, the accumulating top-weight of recent design changes required the addition of deep bulges to either side of Graf Zeppelin's hull, decreasing that ratio to 8.33:1 and giving her the widest beam of any carrier designed prior to 1942.[7] The bulges served mainly to improve Graf Zeppelin's stability but they also gave her an added degree of anti-torpedo protection and increased her operating range because selected compartments were designed to store approximately 1500 tons more fuel oil.[8]
http://en.wikipedia.org/wiki/Graf_Zeppe ... ft_carrier

In rough weather, I would suspect that it was a combination of factors that favoured the Swordfish/Albacores including ASV to allow them a higher probability of finding their home CV, but my point was that with a more rugged LG, the Fulmar and Sea Hurricane should be operable under a wider range of sea states than the 109T, and in theory having a lower accident rate at the same time.