First off, we must remember there was no "automatic plotting" in those days and those recording information probably would find it difficult to imagine their records being scrutinised so closely over a century later.
Looking at the Groos' diagram showing the British en echelon on a line of bearing on Lion's starboard quarter so each ship is leaving her smoke in between her next astern and the enemy, it is difficult to see how Lion can sheer out to starboard without crossing Princess Royal's bows. This plan shows the whole BCS turning c.30 degrees to starboard simultaneously some time significantly after 16:00. Groos' presence at the battle and the detail in his representation of British courses and formation may give an impression of accuracy which is not always valid. It would be interesting if McCartney had plotted the actual wreck sites against Groos' estimated locations as well as Harper's.
Harper only plots Lion's course and does not show the identified deviation. His post war contretemps with Beatty and allegations of plot manipulation are well known but in none of his writings does he identify anything amiss with Lion's course around 16:00. Obviously he didn't get hold of the Gunnery Log. Maybe not accounting for this significant deviation is why he retrospectively gets Indefatigable's position wrong, extrapolating backwards from a later Lion position.
Ascribing "motives" to unrecorded variations in courses:
Is a little contentious IMHO wmh829386. I have no doubt Paschen faithfully recorded what he saw and your excellent research of the Lion Gunnery Log independently confirms this. But he then goes on to make a meal out of it.while the BCF (Beatty) have plenty of reasons to not show the true states of his line.
the fact is not mentioned in our opponent’s accounts and is only alluded to inaccurately as a turning away of the whole line
These are plainly allegations of some sort of deception without allowing that they may originate in simple errors. Chatfield's ship was under a hail of fire, and he and others may have been more interested in the potential magazine explosion brewing amidships, giving orders for damage control etc and let their attention drift from the course being maintained. Not mention Indefatigable blowing up. A 5 degree helm order when travelling at near 28 knots would be quite extreme, I suspect, but then I have no personal experience of battleship ship handling. The Naval Manual suggests 15 degrees gives the tightest tactical circle, but this and higher values create enormous drag.
Lion recorded a range cut of 23,000 yds,
Altogether, Lion had opened the range by three miles.
I suspect an increase of 6,000yds in 12 minutes from the enemy means a rate 500yds a minute (average)4.12.00, when Lion had once again brought Lutzow back on a R91 target bearing,
We have already established the long range limitations of B & S rangefinders. This value may be hugely in error.
Paschen, having made his point about the enemy flagship being driven from line by Lutzow's fire, acknowledges Lion later resumed her position. He immediately after says:
Staff Skagerrak p 60The opponents worked with strong course changes and were difficult to see in the smoke. The range [ target Princess Royal] quickly changed from 151hm to 130 hm, then quickly out to 190 and then back to 150hm.
So, as suspected from her gunnery log she was altering course too.
wmh829386 you say:
According to Campbell one of her turrets resumed shooting after being hit but was found later to be 19 degrees out of alignment with the director. The benefits of remote direction, spotting and range-finding depend on correlated and continued accurate alignment of these remotely located systems.I do not understand how could she [Tiger] shoot that badly at such ranges. (Or how massively inaccurate her ranges are)
That range change of 1800 yds in two minutes shows some measurements were highly inaccurate.
All the best
wadinga