2S7 Pion

2S7 Pion

1 About Pion Gun

The 2S7 Pion (“peony”) or Malka is a Soviet self-propelled 203mm heavy artillery. “2S7” is its GRAU designation.

It was identified for the first time in 1975 in the Soviet Army and so was called M-1975 by NATO (the 2S4 Tyulpan also received the M-1975 designation), whereas its official designation is SO-203 (2S7). Its design is based on a T-80 chassis[verification needed] carrying an externally mounted 2A44 203 mm gun on the hull rear.

For more see: https://en.wikipedia.org/wiki/2S7_Pion https://militaryarms.ru/voennaya-texnika/boevye-mashiny/203-mm-samoxodnaya-pushka-2s7-pion/

2 Data

All data for long range guns (LRG) is here: https://en.wikipedia.org/wiki/List_of_railway_artillery

Some interesting statistics is here:http://rpubs.com/alex-lev/357849

library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(DT)
lrg <- read.delim("lrg.txt")
datatable(lrg)

3 Linear Regression Model

Here we fit linear regression model for data with Range_M < 70000. For more about linear model see: https://rpubs.com/alex-lev/360385

lrg2 <- lrg%>%filter(Range_M<70000)
fit.lrg.2 <- lm(Range_M~Velocity_MPS+Barrel_M+Elevation,data = na.omit(lrg2))
summary(fit.lrg.2)
## 
## Call:
## lm(formula = Range_M ~ Velocity_MPS + Barrel_M + Elevation, data = na.omit(lrg2))
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -14153.6  -1985.0    -60.7   2916.1   7010.3 
## 
## Coefficients:
##                Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  -44325.420   6863.817  -6.458 2.69e-06 ***
## Velocity_MPS     59.200      7.428   7.970 1.24e-07 ***
## Barrel_M        736.305    182.142   4.042 0.000637 ***
## Elevation       411.624    116.034   3.547 0.002020 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 5075 on 20 degrees of freedom
## Multiple R-squared:  0.8804, Adjusted R-squared:  0.8624 
## F-statistic: 49.06 on 3 and 20 DF,  p-value: 2.096e-09

4 Predicting 2S7 Pion Range

Here we apply open source data on 2S7 Pion.

predict(fit.lrg.2,newdata = data.frame(Velocity_MPS=960,Barrel_M=11.23,Elevation=60),
        interval = "conf",level = 0.99)
##        fit      lwr      upr
## 1 45472.97 38873.55 52072.39

\[P(38873.55<Range<52072.39)=0.99\] \[M[Range]=45472.97\]

5 Conclusion

  1. Linear regression model Range_M~Velocity_MPS+Barrel_M+Elevation is the best for fitting historical long range guns data (\(Range < 70 km\)).
  2. Applying model on real heavy artillery gun 2S7 Pion we have got nice result for the range of fire.