copy pasting the portion dealing with the evolution of Dhanush for posterity. there would be some format errors i could not overcome. Karan M posted the link -
http://www.claws.in/images/events/pdf/1 ... il2014.pdf
Changes in Policies to Accelerate Indigenisation: Shri N K Sinha, General
Manager, Gun Carriage Factory
As we all know that the Bofors gun was last supplied to this country in 1989 and
thereafter for historical reasons there could not be any further progress of the
operationalization of the ToT. We had received certain documents, with which we
have now completed the evolution of the gun system in our own country; we have
also upgraded the 39 calibre gun to 45 calibre. In my presentation today I am going
to cover my talk in four stages. The first stage is the process prior to seeking DAC
approval for Ordnance Factory Board to manufacture this gun and what all has gone
to manufacturing this gun system. In the second stage, I would like to spend some
time on the DHANUSH Model that was adopted for this project and so far it has
proved that we are quite successful. In the third stage, I would like to bring forward
the contribution of the users, the partnership between the user, OFB and all other
stakeholders which has contributed in such fast development of the weapon system
and finally, I would like to conclude my presentation with the crucial takeaways from
this project.
As I mentioned, the last gun was supplied to this country in 1989. And
thereafter, there is no further progress on the operationalisation of ToT
agreement. Therefore, Ordnance Factory Board in consultation with the Armed
Forces conducted development of certain crucial spares that may be required
for keeping gun system operational. Way back in 1990 the effort to develop these
spares was initiated. Simultaneously, we also started developing an upgrade on 130
mm gun chassis for 155/45 caliber gun system. Three factories in the Ordnance
Factory Board that is Ordnance Factory at Kanpur, Field Gun Factory, Kanpur and
Gun Carriage Factory, Jabalpur started development of these. Between 1993 and
1999, three different versions of the upgrade for development were progressed. The
first gun which was developed, with a breech screw similar to the one available on
Bofors. The second one was developed with a sliding breech that was developed by
Ordnance Factory Board designers. And the third, with 45 caliber barrel with sliding
breech screw. The final version of the upgrade was proof fired and all the
parameters were established. This was the first step which laid the foundation for
the development of a 155/45 calibre Dhanush today. But after 1999, there was a lull
and no further work or development in productionising of this particular weapon
system was undertaken. In 2002 once again in a meeting with Chairman as MGO,
the proposal for development of a gun system was discussed. The first proposal was
for upgrade of existing 155/39 gun to 45 caliber gun and the Ordnance Factory
Board during that presentation made a pitch for development of this gun. It was also
proposed that we upgrade one of the guns electronic systems and electronic
sighting. This proposal was accepted by Army Headquarters. OFB then started with
these projects as an R & D project. Internal R &D project office of Ordnance Factory
Board was chosen and a barrel design was finalized by OFB engineers, which was
shared with CQA (Metallurgy) for validation and inspection coverage. At this stage
one of the international suppliers, SAGEM offered an INS to be mounted on this gun
system. It was accessed that a upgrade of 45 calibre which generate the kind of
forces which will not be possible to be absorbed by the muzzle brake provided on the
Bofors gun. So therefore it was necessary that a muzzle brake be subsequently
designed and also the integrated on this barrel with the breech ring, which also had
to be developed. With these design issues in mind, specific Design Review
Committee was formed. Chairman of the Upgradation Committee was GM, GCF and
that was the beginning of design effort for a new barrel, new muzzle brake and
integration. Three Product Development Committees were formed, one each for
breech and breech mechanism, carriage and muzzle brake with the involvement of
stakeholders such as DGQA, OFB and DRDO.
Between 2004 and 2005, we developed the barrel of 155/45 and it was test fired in
September in 2004 at PXE, Balasore. The 1st strength proof for 155x45 calibre barrel
was done in Jan 2005 was supervised by representatives from SQA (Weapons),
SQAE(Ammunition) and GCF. This particular ordnance had a muzzle brake which
was newly designed Vaned Slot Muzzle Brake. The result of the firing was very
fulfilling, satisfactory while length and maximum pressure was quite satisfactory and
could be adopted. However, during different stages of design evolution, concerns
was expressed about these muzzle brake. After detailed analysis of various
parameters of barrel performance it was concluded that this particular muzzle brake
may not work, it has to be changed and a modified double baffle brake modified
muzzle brake was considered to be a suitable option. The evaluation constituted
many firings including comparative firing between L/39 and L/45 barrels, the carriage
though at that stage was the same. The modified double baffle muzzle brake was
designed and trials were conducted and it was found that the maximum pressure of
buffer and recoil length were observed to be well within limits of original ordnance
139/45 gun system. And therefore this design was found to be acceptable. The
efficiency which was available in the original muzzle brake of Bofors was 33% was
further improved up to 53% in the case of double baffle muzzle break and as a result
of that the forces on the gun structure was substantially reduced and there was no
significant change required in the gun system.
Simultaneously we also developed and integrated an electronic suite completely with
gun system. This electronic suite was again supplied by Bharat Electronics Limited
and we had been able to integrate that with the gun and we fired electronically
upgraded gun system at Balasore. Both the firings were successful. After the
success of these initial firing, range and accuracy firing also was done at PFFR.
I will now bring out certain comparative characteristics of these two guns. The Bofors
39 and Dhanush. The barrel length increased almost by one meter and the weight of
the barrel increased by 200 kgs approximately. The ordnance weight similarly
increased by 200 kgs. The chamber capacity, that was one significant design
increased frem 19 to 23 litres. Maximum range consequently increased to 39 kms
and the muzzle velocity increased marginally. Auto frettage of the barrel which was
done at Gun Factory Kanpur was increased to 675 mpi. The type of ammunition that
could be used in the upgraded gun system included almost all varieties. The upgrade
was also made compatible for taking BMCS ammunition of highest charge. After the
firing in 2008, where all parameters of the newly developed gun system were
validated, i.e., after three years of successful first test firing of the gun, in 2011
Defence Acquisition Council accorded AoN for 155 mm x 45 Cal Gun System for
procurement from OFB.
The Dhanush Model : I would like to share the experience of recent Dhanush
performance in sub zero temperatures in Sikkim which implies that it is satisfactorily
working in the extreme climatic conditions and performing admirably. Dhanush
today has 23 major assemblies and 874 sub-assemblies, 80% of which have
been indigenized. The system has 3430 manufactured items/sub-systems
which have been mostly manufactured in house by OFB and about 4902
bought out items, which are being looked at for indigenisation.
Evolution of Dhanush, started out from upgrades done in the 2008 to another
upgrade in January 2012 155 mm FH Electronics and 155 mm FH Project
DhanushOFB Prototype -1 in Dec 2012. Finally, in 2013-14 OFB Prototypes -
3,4,5 and 6 were developed. Step by step development of Dhanush was
undertaken which meant that the major sub-assemblies were manufactured
separately in stages. We changed the indigenous components, one by one and
proof fired them to establish the correctness of the manufacturing process.
To this end before we took two guns from Army. The first one was upgraded with the
45 calibre barrel and the complimentary components. The second one was
upgraded electronically and both these gun successfully proof fired at Balasore. The
success of these two gun systems helped us in taking the next step forward. At this
stage we were to decide whether to go in for 45 or 39 calibre gun systems. But
seeing the success of the upgraded 45 calibre gun, it was then concluded that we
should further proceed on the same path by developing 45 calibre gun systems only.
Both these guns developed had 45 to 65% of indigenisation components at
that stage. Both these were test fired at Balasore and proved to be quite
satisfactory. In January 2013 we had a demonstration firing of these weapons at
Pokhran. Many of the senior officers of the Army witnessed the performance of these
guns. From January 2013 to end of the year, OFB carried out several firings in
different locations in the country. The prototype number three was manufactured in
April and successfully test fired at Pokhran. The fourth gun was subsequently
manufactured and taken for user trials, which is where as many of us know the
unfortunate incident took place. As a result, detailed analysis was again conducted
and the barrel and structural designs revisited, which clarified that there was no
deficiencies in the gun system. The fifth prototype was developed after two months
and recently trial evaluated in Sikkim.
Associations and Stakeholders: The project was progressed by the active
involvement and commitment of all stakeholders. Indian Army as Users provided
support, monitoring and coordination. DRDO was responsible for design support,
DGQA for proof testing and validation, SAIL as suppliers of micro alloy steel plates,
506 ABW as partners in development and maintenance and BEL supported the
Electrical & Electronic Modules for the sighting system and electronic suite.
Associations and contributions of the different organisations within OFB as well as
other DPSUs and private sector in the development and manufacture of Dhanush
gun systems have been noteworthy, particularly for laser cutting, fabrication,
machining, integration & assembly of Dhanush prototype by GCF, Wheels by
Wheels India, MRF, DLSI, Braking system by WABCO, Hydraulic systems by
DANTAL, Power plant by DLSI, Investment castings by OFM, Heavy steel castings
by OFM, Micro alloy steel plates by SAIL, metal and forging by MSF, Ordnance by
OFC/FGK, Electronic suite and electrical by BEL, Wheel base assembly by MTPF,
Structural items by Punj Lloyd.
Major sub-assemblies indigenized in India are chassis manufactured by GCF,
Jabalpur from the micro alloy steel plates which were supplied by SAIL. The
outcome of the indigenasation is primarily in hydraulics which has indigenised from
20% to 100%, pneumatics from Zero to 100 % and Electrical/ Electronics from 46
sub assemblies to 112 sub assemblies.
Development Milestones: The milestones ranged from the mechanical upgrades
of in-service 39 to 45 calibre which was proof fired within four months, mechanical
and electronic upgrades of L/39 to L/45 gun which were validated for trials within
nine months. Building of the 1st and 2nd prototypes, conduct of several validation
firings within 15 months and finally, development of the 3rd prototype, PQSR trials
were done in 17 months. Now, three more prototypes manufactured and user trials
are in progress. Role/involvement of user in the development and manufacture
of Dhanush is a project monitoring model at four levels; Multi-Tiered Special
Project Management Group located at IHQ and GCF which is the Apex Board,
next is Weapon Design & Development Steering Committee followed by
Weapon Design & Development Committee and Weapon Design &
Development team and, finally Weapon Development & Execution Team
(WDET).
Charter for WDET: WDET worked as a single point referral and coordination agency with user for efficient execution and time bound activity including
anticipatory, actions by users, designers and manufacturing agencies. Weekly
monitoring of production and development of outsourced components and conduct
and coordinate testing/evaluation also was a part of their charter and, finally,
implementation of user, feedback into redesign/upgrading of components.
Conceptualization in maintenance/repair schedule and lifetime spare.
Role/Involvement of EME: 506 Army Base Workshops were permanent members
in WDET and part of the initial training to core team on gun assembly, testing of
hydraulic and gun systems, maintenance cover during trials and support in
indigenisation of sub assy.
Role/Involvement of DGQA & DRDO: DGQA provided support in proof testing,
proactive participation in development and design validation while DRDO was
involved in the areas of design validation, range tables and technical/design support.
The crucial takeaways from the project are the synergy between user, designer
and manufacturer, single window user interface, need for compressing trial
and evaluation times, flexible procurement provisions, and access to
specialized design validation and testing agencies.