8 March 1990
Control sample laminates tested – continuation of resin test
According to Harrower’s statement (AC) and his ch10 CP, after the visit to Ciba
Geigy on 8 February he made contact with a number of companies involved in the
production of fibreglass laminate used in the manufacture of PCBs, and obtained
samples of the various laminates they produced for comparison with PT/35(b).
He received in total 23 different sample laminates from producers in Europe and the
Middle East, which he understood covered all the production companies, and he
produced DP/143 (prod 337), a schedule showing the laminate samples and suppliers.
He provided the 23 samples to John French at Ciba on 8 March 1990 for comparative
analysis. He later obtained a statement from French of the results of the analysis
(neither Williamson nor Harrower’s statements specify when the results were
obtained from French).
According to Williamson’s memo of 16 March 1990 to the SIO another of the “other
enquiries” that was carried out was that contact was made on several occasions with
Len Pillenger of British Telecom’s quality approval dept. Mr Pillenger apparently
provided a number of sample laminate boards from a library of information and
samples that he had, and according to Williamson’s memo the samples that he
provided were valuable in comparison at the tests carried out at Ciba Geigy.
It therefore seems that Pillenger was the source of some of the 23 samples that were
tested on 8 March 1990. The exact details of these samples or the discussions with
Pillenger are not disclosed, nor are the dates of these discussions. There is no
HOLMES statement for Pillenger.
According to French’s HOLMES statement after his analysis of the various samples
he found that two types of laminate, Ditron (manufactured in Italy) and Sefolam
(manufactured in Israel) were the closest match to the spectrum obtained from DP/12,
and he provided DP/139 (in fact this should read DP/18, prod 336 – it appears that the
designations of the two spectra printouts produced by French were mistaken for each
other in the HOLMES statements, as DP/139 is the spectra printout provided on 8
February, above), a spectra printout showing the laminates listed in DP/143 that
closest matched PT/35(b).
In French’s CP he basically confirmed this account of events, but stated that he had not seen the schedule of samples, DP/143, before. He also said he tested the fragment PT/35(b) again on this second visit by police, and he said a clearer printout was achieved on this occasion. He noted from the spectra printout DP/18 that solder mask traces were found on the non-track side of the fragment.
He stated in his CP that Williamson had produced a statement and
provided a copy to him, and he had referred to this prior to the precognition. He had
very little memory of the subsequent visit by police in 1992 (see below) which would
suggest that his memories in his CP must have relied on the contents of the police
statement. According to French’s CP and DP, he provided the outcome of his
analysis in the form of a letter dated 9 March 90, and in his defence precognition he
said the police then incorporated the letter into a statement. He apparently produced a
copy of the letter at his Crown precognition.
According to Williamson’s defence precognition, “some time later” he received the information about Ditron and Sefolam, and then later he had tests carried out by Dr David Johnson at the University of Manchester (see 23 May 90, below). In Williamson’s memo to the SIO of 16 March 1990 he reported that French said the fact that PT/35(b) was exposed to extreme heat could have had an effect on the results of the analysis and that, although
Ditron and Sefolam were the closest matches, this could in no way be viewed as conclusive.