Impactos de Implementación y Selección de Arquitectura

The Leopard 2A4M tank is also a fighting vehicle, primarily used to provide direct weapon fire support; with the vehicle designed primarily for the mobility and survivability of the primary weapon system. When compared to the LAV III-ISC, a larger proportion of its GVW is the curb weight; mostly due to requirements for the primary weapon system and armoured protection.

Figure 4.6 – Leopard 2A4M tank

Table 4.8 shows five flown “weights” from the NMDS database for Leopard 2A4M. The curb “weight” has a bias coefficient of 1.005 with respect to the nominal air shipping “weight” of 56,074 kg (Leopard Requirements Officer, Director Land

Requirements 3-4-3, Department of National Defence, 2013)with a CoV of 0.016. The NMDS database does not capture the level of fuel in each transported vehicle (1,200 litres when fully fuelled, nominally 300 litres for transport), or if some components normally removed from the vehicle for transport, such as the chassis Add-on-Armour (AoA), were not removed. Some weight differences shown in Table 4.8 may be attributed to differing volumes of fuel within the vehicle and chassis AoA not removed for transport. Of the five Leopard 2A4M tanks shown, one has a notably higher

“weight”, 58,163 kg. This closely approximates the “weight” of a Leopard 2A4M with chassis AoA in place, which is 58,424 kg if 300 litres of fuel is included. The bias coefficient and CoV of the remaining four vehicles are 0.997 and 0.004, respectively. Therefore, it is reasonable to assume that the weights of components of the Leopard 2A4M are deterministic, at least when flown.

Table 4.8 – DND NMDS flown vehicle “weights” for Leopard 2A4M tank

Dispatch Date CFR Mass (kg) 18/Nov/2011 72308 55,684 29/Nov/2011 72334 55,802 29/Nov/2011 72301 56,001 29/Nov/2011 72321 56,214 29/Nov/2011 72316 58,163

Table 4.9 presents the assumptions adopted to idealize the various load

components of the Leopard 2A4M tank GVW. The deterministic curb weight, 59,484 kg, consists of the Leopard 2A4M tank chassis, main gun and turret, AoA, slat armour

system, and a full tank of fuel. The crew consisting of four persons at 75 kg each is also assumed deterministic. The nominal masses of the various operational weights are quantified from various DND sources and are sufficient to increase the nominal curb weight to the nominal combat weight. These operational weights are assumed to vary uniformly across the range of each parameter shown, which is intended to conservatively envelope (by disallowing the consideration of vehicles lower than the nominal combat weight) the actual parameter range as determined given the range of possible operational considerations. The potential for an additional operational load of up to ten infantry riding on top of the tank was also considered.

Table 4.9 – Leopard 2A4M tank operational loads Component of GVW Nominal Quantity Combined Nominal Mass (kg)[a] Assumed “Weight” Variability for Idealization Notes Curb “Weight” (fully fueled with AoA and

Slat Armour)

- 59,184 Deterministic

Crew 4 300 Deterministic 75 kg per person

Payload A - 1,000 (Total Nominal)*(Uniform Distribution between 1 and 1.5) Inventoried Items Payload B - 730 (Total Nominal)*(Uniform Distribution between 1 and 2) Miscellaneous Equipment / Stowage Infantry Section Transport 0 0 (Discrete Uniform Distribution between 0 and 10) Mass of each soldier 136.5 kg [b] Total “Weight” 61,214

[a] Leopard Requirements Officer, Director Land Requirements 3-4-3, Department of National Defence, (2013)

[b] Emergency Approach Load (US Army Center for Army Lessons Learned, 2003)

Figure 4.7 shows the cumulative distribution for 10,000 Leopard 2A4M tank weights that were randomly generated assuming the load components shown in Table 4.9 are independent. Above the 35th percentile, Weibull distribution has an excellent fit to the simulated data, (passing the K-S test at a significance level of 10%). The CDF of a Weibull distribution has the form:

[4.15] ⁄

Figure 4.7 – Weibull distribution for simulated Leopard 2A4M tank GVWs The event and annual maximum statistical parameters for the Leopard 2A4M tank are shown in Table 4.10. The Leopard 2A4M GVW has negligible variability.

Table 4.10 – GVW of Leopard 2A4M tank

Leopard 2A4M Nominal “Weights”

Curb / Combat [a]

Weibull or Gumbel Parameters

Event (Weibull)

Maximum Annual (Gumbel) 100 1,000 10,000 100,000 59,184 kg / 61,214 kg (kg) 62,710 63,523 63,743 63,900 64,021 or β (kg) 118 105 73 56 45 Bias 1.021 1.039 1.042 1.044 1.046 CoV 0.008 0.002 0.001 0.001 0.001

[a] Leopard Requirements Officer, Director Land Requirements 3-4-3, Department of National Defence (2013)

Although limited data are available on measured weights of tanks and infantry fighting vehicles (like the LAV III-ISC) at combat weight, Engeler (1994) persents detailed weights of two prototypes of the Austrian Spanish Cooperation Development (ASCOD) armoured fighting vehicle with all crew members and equipment simulated with the use of sand bags. The bias coefficient of the weight of these prototypes are similar to the estimated event bias coefficients calcuated for the both the LAV III-ISC and Leopard 2A4M tanks. The six-roadwheeled (the roadwheel is the wheel that holds

the track in place and transfers loads from the vehicle to the track, but does not contribute to driving power) prototype PT2 has a bias coefficient of 0.993 with respect to the

nominal combat “weight” of 27,340 kg, and the 7-roadwheeled prototype PT3 has a bias coefficient of 1.012 with respect to the nominal combat “weight” of 27,969 kg (Engeler, 1994). Although more information would be required to assess the accuracy of the statistical parameters for weight presented in this thesis, the independent corraboration of bias coefficients for similar vehicles adds some confidence to the approach.

4.2

Relationship between Payload Weight Fraction and