MxV Rail · Digitronix
TD Chat: what
we've fixed,
and why
8 September 2026 · Presented by Fadzi Mkandla
01 / 20
Status · 8 September

Where things stand

Every problem you told us about has a fix, built and working on our test site. The last step, rebuilding the search library the new way, is happening now.

After that: we test it, you test it, a quiet fortnight, then live.

YOU ARE HERE Fixes built Rebuild, now Our tests Your tests Live
02 / 20
Your issues · six items

Your issues, in your words

1
“Vertical split head” found nothing, though the old search found three Digests.
Fixed, on our test site
2
Asking for a Digest by its number: two of three came back empty.
Waiting on the rebuild
3
Asking for an author's work missed most of it.
Waiting on the rebuild
4
“Did ENSCO become MxV Rail?” got an invented answer.
Fixed, on our test site
5
The old search button jumped to the chat tab.
Fixed, you confirmed it
6
Citations pointing to documents that do not exist.
Fixed, on our test site
03 / 20
How it works

How the chat works

Think of a library with a fast assistant and a writer. Every Digest is cut into pages, and each page gets a catalogue card saying what it is about.

Your question is matched against the cards, and the ten best pages go to the writer, who answers only from those ten.

If the right pages are not found, the writer cannot give the right answer, whatever settings we change.

BUILDING THE LIBRARY DIGEST PAGES CARDS THE LIBRARY ANSWERING A QUESTION Your question ITS CARD TEN BEST PAGES CITED ANSWER
04 / 20
Diagnosis

The Digests were always there. The search could not find them.

Nine Digests contain the phrase “vertical split head”. TD18-032 says it 28 times. The search found none of them.

Three reasons: the pages were too long (about 500 words, several topics each), the cards carried no number, title, year or author, and the search could not match exact words at all.

Not a temperature problem. It was already at its lowest, and the wrong answers were consistent. That told us the search was at fault.

9 CONTAIN THE PHRASE 0 WERE FOUND THREE REASONS PAGES TOO LONG NO LABELS VSH NO EXACT WORDS
05 / 20
Fix 1 of 11 · Issue 1

Fix 1: Shorter pages

Pages were about 500 words. Now they are about 200. A short page is about one thing, so it matches a specific question far better.

And because pages are shorter, the writer can be given three times as many for the same cost.

More evidence behind every answer.

Waiting on the rebuild
BEFORE: ONE LONG PAGE NOW: SHORT PAGES 10 PAGES PER ANSWER ABOUT 30 NOW
06 / 20
Fix 2 of 11 · Issues 2 and 3

Fix 2: A label on every page

Every page now carries its Digest number, title, year and author, written into the page itself so the search can read it.

That is what sends “summarise TD99-002” straight to TD99-002, and what makes author searches work. Author names are filled in automatically. Where one person appears under several spellings, we tidy those by hand.

Waiting on the rebuildName spellings: needs your input
LABEL LINE ON THE PAGE ONE PAGE TD99-002 Rail-Defect Test Facility · 1999 · Garcia, Reiff WRITTEN INTO THE PAGE THREE SPELLINGS SPELLING 1 SPELLING 2 SPELLING 3 ONE AUTHOR NEEDS YOUR INPUT
07 / 20
Fix 3 of 11 · Every search

Fix 3: Searching in the right mode

The search engine has two modes: one for filing documents, one for answering questions. The live site used the filing mode for both.

Questions now use the question mode.

One line of code. Every search a little sharper.

Fixed, on our test site
FILING MODE USED UNTIL NOW QUESTION MODE · NOW
08 / 20
Fix 4 of 11 · Issue 1

Fix 4: Exact words and meaning, together

The old search matched exact words. The chat matched meaning only. Rail terms and acronyms need exact words; open questions need meaning.

The chat now does both and merges the results.

“Vertical split head”: your three Digests, 0 of 3 found before, 3 of 3 now.

Fixed, on our test site
Still being tuned for terms not yet in the glossary.
EXACT WORDS MEANING MERGED 1 2 3 4 5 0 of 3 3 of 3 BEFORE NOW, ON OUR TEST SITE
09 / 20
Fix 5 of 11 · Acronyms

Fix 5: A glossary of your terms

“VSH” and “vertical split head” now mean the same thing to the search. The glossary lives in the admin area.

It starts with four entries and needs many more: BHC, RCF, ECP, UTP, TTC, FRA and the rest.

We need an acronym list from MxV Rail.

Fixed, on our test siteGlossary: needs your input
GLOSSARY · ADMIN AREA VSH vertical split head BHC RCF ECP ALSO UTP · TTC · FRA ADD ENTRY
10 / 20
Fix 6 of 11 · Issue 3

Fix 6: Author searches that use the author's name

“Publications by Duane E. Otter” used to rely on the search guessing a name. It found 2 relevant Digests in 10.

Now the author is written on every page and the search filters on it: 9 in 10 on our test site.

Once every author is filled in, you get the full list, not a sample.

Fixed, on our test siteFull author list: waiting on the rebuild
BEFORE 2 of 10 NOW 9 of 10 ON OUR TEST SITE
11 / 20
Fix 7 of 11 · Breadth

Fix 7: No single Digest hogging the answer

One Digest with a lot to say could fill all ten pages and crowd out the rest.

There is now a limit per Digest, so a question like “which Digests discuss wheel flange wear” draws on several.

Fixed, on our test site
BEFORE: ONE DIGEST ONE DIGEST FILLS TEN NOW: SEVERAL DIGESTS LIMIT PER DIGEST FOUR DIGESTS ANSWER
12 / 20
Fix 8 of 11 · Issues 4 and 6

Fix 8: An honest “not found”

Before, “Did ENSCO become MxV Rail?” got an invented history, because ten loosely related pages were handed to the writer as if they were evidence.

Now: “No. The retrieved MxV Rail sources do not provide information about ENSCO becoming MxV Rail.”

Every citation is checked against the library before it is shown, so made-up filenames cannot appear.

Fixed, on our test site
BEFORE Did ENSCO become MxV Rail? INVENTED NOW Did ENSCO become MxV Rail? No.The retrieved MxV Rail sourcesdo not provide informationabout ENSCO becoming MxV Rail. HONEST OFF-TOPIC TEST REFUSED CITATIONS CHECKED
13 / 20
Fix 9 of 11 · Issues 2 and 3

Fix 9: Summaries by Digest number, and by author

“Summarise TD98-015” and “TD18-032” now give correct, cited summaries. TD99-002 showed the last gap: its PDF writes the number as “TD-99-002”, so the search missed it and summarised the nearest Digest instead. The label on every page (Fix 2) closes that.

“Summarise Stephen Wilk's publications” returned 8 Digests, all correct, out of 56. The full 56 come once every author is filled in.

Waiting on the rebuild
TD98-015 CORRECT, CITED TD18-032 CORRECT, CITED TD99-002 THE LAST GAP THE PDF WRITES IT AS TD-99-002 TD99-007 WRONG DIGEST BEFORE LABEL: TD99-002 TD99-002 RIGHT DIGEST NOW
14 / 20
Fix 10 of 11 · Issue 5

Fix 10: The search button, and the footnotes

The old search no longer jumps to the chat tab. Fixed on the live site on 25 August, and you confirmed it the same day.

Footnote numbers used to reload the page. They now jump to the reference.

Fixed, you confirmed itFootnotes: fixed, on our test site
TD SEARCH TD CHAT SEARCH NO MORE JUMP FIXED 25 AUGUST FOOTNOTE 1 1 THE REFERENCE JUMPS TO REFERENCE
15 / 20
Fix 11 of 11 · Visibility

Fix 11: We can now see every search

Until now we only learned of a bad answer when you told us. The chat now keeps a log of every question and what it cited.

We propose keeping it for 30 days.

We need a yes from MxV Rail on keeping question text and IP addresses for 30 days.

Fixed, on our test sitePolicy: needs your input
QUESTIONTIMECITED NONE EVERY QUESTION LOGGED 30 days PROPOSED WE NEED YOUR YES
16 / 20
The step in progress

Rebuilding the library without touching the live site

The new library is built next to the old one, tested, and only then switched in. The old one is kept in case we need to switch back.

Nothing you use today changes until that switch. This is the step happening now.

Waiting on the rebuild
LIVE LIBRARY NEW LIBRARY KEPT FOR ROLLBACK SERVING NOW TESTED AFTER THE SWITCH THE LIVE SITE
17 / 20
Proof · the 18 test questions

How we will prove it before you see it

18 test questions, built from your own. Each has a pass mark. Today on our test site, with the new code but the old library: 10 pass, 3 nearly, 5 fail.

01
vertical split head
02
vertical split head vsh
03
What is VSH?
04
BHC
05
bolt hole crack
06
gauntlet track
07
Duane E. Otter
08
A. John Peters list
09
Peters, wheel wear
10
ENSCO
11
western vs eastern
12
wheel flange wear
13
off-topic test
14
ultrasonic rail head
15
summarise TD99-002
16
summarise TD-99-002
17
Wilk summary
18
VSH summary
10 · 3 · 5 today
10 pass3 nearly5 fail

The 5 fails are exactly the ones waiting on the rebuild. We have the “before” scores from 3 August, so improvement is shown in numbers, not impressions.

18 / 20
Next · sequence, no dates

What happens next, and what we need from you

1 2 3 4 5
The rebuild finishes.
We run the 18 tests and send you the scores.
You test on our staging site with your own questions.
Two quiet weeks with no new problems.
Live.
Three asks
Your acronym list Author name spellings, or who to ask A yes on 30-day logging
Offer: your own login to the staging site as soon as step 2 passes.
19 / 20
Thank you
Fadzi Mkandla fadzi.m@digitronix.co.uk
Kaylee Avis kaylee.a@digitronix.co.uk
20 / 20
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